Looks like you're tying revamping content with less content as a whole- certainly redoing something takes resources but having to redo MCH for example wouldn't exclusively explain the difference from 2.0 to 5.0 as were revamps between those points as well. That and also looks like you do want revamps of some content, just that the content that has received it you didn't feel worth it for whatever reason.
All in all to say the devil it seems you're focusing on is the reduced content and not the redo in and of itself as a concept. Like if you revamped say chocobo content such that it had new content that had some relevance and gameplay content that's not like revamping say a perfectly well enjoyed job (say if they revamped Paladin entirely, I hardly hear people complain about that job). There was a feeling of changing a job you liked away from that feeling but you also mentioned some items that you would appreciate some changes to, so it's not revamping that was bad but what that you didn't appreciate.
If the content is really bad I think it's worth it as while not exactly like rotting food I still think it has a vaguely similar effect. Rotten apple spoils the bunch, unlike food it doesn't have to spread but it can mar the experience which might feel like spoil spreading. That and sometimes revamps / redos can provide a much better and or deeper experience, beyond polishing it up and making the whole package look well done.
I have also noticed some reduced content points, and am personally hoping it's because they're preparing something cool - maybe the expansion is going to have some neat new feature or expanded something further than they would normally (say if they wanted to end the main story they've been working on so far with a huge huge bang). Now of course it's possible they're just trying to save money (number of possible reasons, some eh some reasonable), or they're moving it over to other another project lol.