This question pertains not only to today's ground-breaking moments, but the collection of historical data as well. I would assume in the past, books/memoirs/letters sent between people could paint a picture of what was going on centuries ago. However, due to the vast information on the internet that could potentially skew the facts, do you think that writing the history of today could prove difficult to future historians?
A big part of learning the history of any era is sorting through accounts with conflicting perspectives, isn't it?
I think that the massive amount of recorded data from the present era will make it relatively easy for future generations to understand what was going on, even if population growth doesn't necessarily continue at the same rate. Information today is much easier to come by and to process than at any other time. Having more accounts to sort through means that superficial conclusions are far less likely to go untested.
Assuming all that information persists and survives (which it easily might not), easier, I think.
History is as much a reflection of the current world/society, its biases, outlook, perspectives, etc, as it is about those who left us their writings, architecture, artifacts, the detritus of their daily lives.
So, our great-grandchildren (if humanity survives that long) will look for what they want to see. And thanks to the vast amounts of information available, they will find it more easily.
A big change will be the development of big data. The mid 20th century is incredibly hard because of the vast amounts of material. There's literally miles of archives. Big data will allow us to examine issues across a huge range of sources all at once. There are some real problems about preserving sources. It's already hard to access a wordperfect document on a 5.25" disc. Imagine trying to preserve iCloud if Apple went bust.