No it should not “be replaced”. See here, and the following discussion.
You are involved in a series of “tag changing adventures” that have already been reverted once where someone previously cocked it up. You’ve offered to pick up that work after the previous editor’s errors. Thanks for that, but I would strongly suggest that you complete the jobs that you have started before embarking on other adventures elsewhere.
Data consumers who are interested in this data are presumably just fine with the way it is right now. If mappers mapping new features want to describe it in the new way that people have invented rather than the way that everyone has previously done it, fine - data consumers will deal with it, as they always do.
Hi, there are only a few active OSM contributors in New Zealand, previously the best way to contact everyone has been via the talk-nz mailing list. So far, I can only see 1 other post related to NZ on this new forum.
Personally, I think historic=archaeological_site + ????_type=fortification + fortification_type=pa is the best way of tagging a pā.
historic=pa was invented by the LINZ import in ca. 2009, back when there was no established tagging system (fortification_type had under 100 uses and wasn’t documented until 2017).
There are many other invented tags from the original LINZ import that have been converted to standardized tags over the past 5-10 years. EDIT: Here’s a wiki page with the full list. A few of us have already started changing historic=pa to historic=archaeological_site on a small scale.
I see no reason why we couldn’t upgrade the tags here, but it would be important to discuss this on talk-nz first, in case anyone is consuming historic=pa. It doesn’t look like Te Reo Māori Web Map | The Map Kiwi is using historic=pa although it does seem to use amenity=marae