Are old rev*.dat file safely deletable? based on this answer rev files contains information for dealing with reorgs.
If I think reorg longer than let's say a month are highly unlikely, could I safely delete rev*.dat files older than a month?
No. You need the rev*.dat files as much as you need the blk*.dat files. If Bitcoin Core cannot find the rev*.dat, it will need to regenerate them by reindexing the databases. Removing them effectively corrupts the databases.

If you want to save disk space, you can use pruning instead. This will have Bitcoin Core properly remove blk*.dat and rev*.dat files to save disk space.