I think 'stagnated' would be going a bit too far, but 'local historiography', ie. the history of villages, cities, local regions etc. is very slow moving compared to 'big historiography' that looks at larger developments. So, for example, in larger-scale early modern social historiography, literature older than two or three decades tends to be almost always outdated in regards to modern scholarship (for example, even in literature from the 80s, you can find claims of 'millions' of convicted witches in the context early modern witch hunting, while the number currently supported by modern scholarship is only around a 100k for all of Europe). Meanwhile, from my experience, in local early modern historiography it's not uncommon to refer to literature from the 60s or 70s without major revisions.

(FWIW this is based on my experience with local early modern European historiography, for US historiography it may be different).

Contemporary conflicts have led to the halting of archaeological digs and looting of historical sites. I suspect it will be decades before historians will be able to safely return to Syria, for example, and what they will return to is liable to have been horrifically looted.

You can see some interactive photos of what that looks like here: https://www.theatlantic.com/photo/2016/02/the-looting-of-syrias-archaeological-treasures/459996/