Perhaps this isn't the straight historical perspective that you came for and it may be more in line with a sort of "history of economic thought" take; if that is the case - I preemptively apologize. But I still feel like I need to butt in a moment because the Malthusian trap is often (not always, but often) not fully correctly understood when discussing it from an economic perspective and sometimes the devil is in the details.

The reason I'm saying this is because you directly reference many things that individuals nodding towards Malthus tend to reference. That is, famine, war, natural disaster, basically things that will directly limit population levels through a sort of carrying capacity that we may expect to find if we were discussing something like Ecology. And honestly, there's no fault for that because Malthus himself pulls these sorts of cards out when discussing what are seen as "positive" checks on populations. The things you're listing are events or scenarios where the population is dwindling because they are flat out dying off, where they have overshot their environment's carrying capacity and are simply unable to care for themselves. But isn't quite fully what Malthus was saying and, while not necessarily completely incorrect, it does miss the forest for the trees a bit and fails to properly acknowledge some of the nuances behind what Malthus was trying to convey with his essay.

Malthus was largely attempting to delve into the idea of income and production as it related to population and a better focused on point would be his attention to suggesting that populations experience rapid growth rates once they are no longer limited by their necessary means of subsistence. Once there exists a surplus or excess or however you wish to think of it, then we'd anticipate a population flourish. As these surpluses "dry up", prices climb due to the new increased consumer population (Malthus was particularly focused on agricultural goods), there is some increased mortality but - more importantly - birth rates fall. So it may help to consider that Malthus is arguing a carrying capacity stance but taking acknowledgement of the fact that there will likely be this sort of sinusoidal like action with the population count happening around the capacity.

So what's the point of that whole bit, sounds an awful lot like the Thomas Malthus we all know and love, right? It's important to not think Malthus was arguing from a purely biological or ecological perspective, he was attempting to draw focus on ideas of political economy. Namely, wages. (David Ricardo even used these Malthusian principles as a springboard for what were referred to as "the iron laws of wages".) His point can basically be summed up as follows: there's a population of laborers that are experiencing a wage rate above subsistence level (note that "subsistence" should not be mistaken for "survival", it refers to their current standard of living and their ability to raise a family). Due to the high wage, consumption of agricultural goods increases and population growth occurs as the laborers begin raising families or as foreign laborers enter the market. Agriculture cannot keep up (this is his whole "geometric vs. arithmetic" bit) and the prices of agricultural goods rises. Due to the price rise, real wages decline and we're back to laborers working at the "subsistence level" of their environment. From this, it's easy to see how the reverse stands.

It's almost as though he is suggesting there exists a sort of "natural poverty" (for lack of a better phrasing) and that the only hopes individuals have of standards of living increasing is to limit population growth. Was this idea embraced by economists and states? Partially. Malthus undeniably had his impact and what he's saying isn't without it's grain of truth, but there were other very prominent economic thinkers at the time that had theories that went against some of his proposals. Consider the presupposition that Malthus put on technology and production advancement - he largely assumed a world where "the pie couldn't be made bigger" and took a stance of suggesting that fear of poverty largely ignited industry. (Note that this goes staunchly against economists like Adam Smith, William Godwin, or Marquis de Condorcet, who argued that it was a desire of one to improve one's standard of living that sparked industry.) Ultimately however and more to a part of your central question ("Does rapid population decline, in itself, cause a levelling of social status?") I would argue not necessarily and that likely would have been the sentiment with a number of economists around this time in Europe as well.

There is no doubt that social dynamics and class "behavior" will be impacted, but we really don't have to look much further than to one of Malthus's peers already referenced to see a rebuttal to the pure degree that is being suggested: Godwin.

Godwin's Of Population largely argued against Malthus by suggesting that it was too assumptive to claim population followed an exponential like rate of growth (pointing to how many families did not produce enough children for this to be true), cited the expansive resources of the American colonies as evidence that the "arithmetic" assumption of subsistence was also faulty, and further argued that individuals themselves were capable of seeking higher industry as well as "checking" themselves (essentially following their own individual budget constraints). Further, and as pointed out by other economists, Malthus's approach to wage laws would seem to hinge on a significant lag effect of at least a decade (that is, the time necessary for the labor population to "feel" the influx or outflow of laborers); and this has not been the witnessed case. (Indeed, it's been found that wage fluctuation is more flexible than what may be suggested by that time span.)

Edit: For whatever reason, Reddit didn't seem to like my comment around 75% of the way through and wouldn't let me post it/failed to recognize text in the comment box. Had to do a bit of copy-pasting and then come back in and finish up what I had (hence an "edit" if it shows up).