Primary suggestion:

There have been multiple occasions where I've been working on a document and another user has gone to the version history and reverted the document, causing a loss of work without any immediate explanation so it'd be good to have a little warning so that the user isn't met with confusion and shock.

Secondary suggestion:

Issue -

Even if I were to create a copy of the document prior to reversion to try and salvage what was lost, that pre-reversion version may not be up-to-date and a loss of work is inevitable. This also isn't a viable solution for documents with larger data files

Suggestion -

Reversion needs to be opted in by everyone who is currently active in the document