For completeness, here’s a link to the " Automated Edits code of conduct". That explains what you need to do before changing any data. You’ve already started the first part of that (“Document and discuss your plans”), so thanks for that. The rest of that wiki page explains the rest of what you need to do (proceed with caution; small changes first, etc.).
Although it’s not required by that code of conduct, I’d also suggest contacting the data consumers listed on taginfo for that tag**. This shouldn’t be too much of a chore, as there are only 7 data consumers listed there.
** full disclosure - (wearing my “web map developer” hat) that includes me***. I spotted an earlier iteration of large-scale changes to this tags and discussed it here. Given the chat on the German forum and the fact that I suspect that the other maintainers aren’t living under a rock, I suspect that the other maintainers may know already too - but it’d still be nice to let them know.
*** and also (wearing a “Data Working Group” hat), I’ve picked up a ticket that was reported from with the German community about an undiscussed mass edit. That resulted in a message to the user performing the change that was reported to say that they needed to join the general discussion in the German Forum. So far they seem not to have acted upon that request, unfortunately.