Any major retagging event should be coordinated here, on Meta, because:
This leaves a record of the reasoning behind the mass-retagging, and provides a venue for other users to discuss, dispute, or volunteer to participate in it.
...provides a heads-up for moderators, so that they can help out (by merging tags when possible, or by simply retagging along with everyone else).
...provides a heads-up for Stack Exchange, so that we can provide assistance and advice.
We don't want to just disable bumping for any user, since this leaves the door open for someone with a bright idea to really make a mess of things without being noticed. I've personally observed otherwise-savvy, experienced users on other sites decide they had created some brilliant new taxonomy, and tear apart the existing structure to make it fit their own preferences - this can be... problematic.
So the best advice I have for now is to get organized, and get as many willing users involved in these retagging efforts as possible - so if you must disturb the main page, you're not doing it for very long.