[thereddaikon]

>But how, then, are we to recognize paradigm shifts?

The strength of the argument and supporting evidence. Big claims need big evidence. Simple as. One problem specifically in history today is many historians can get by their whole career by being an X historian where X is some political ideology or social science construct. They can write endless papers analyzing existing work through that lense whether or not it makes sense to do so or really adds anything to the body of work. This is where a lot of revisionist history comes from. They aren't performing original research and finding new evidence and sources. They are merely critiquing the work of others through their chosen lense.

The worst form of revisionist history is of course just denying the facts as they are known and inventing your own. But thats is rare within serious academia these days with a few notable exceptions.