First of all, let me preface by saying I’m pretty ambivalent on mapping census geographies in OSM. I tried to maintain CDP boundaries in Ohio for a time, reasoning that we might as well have accurate boundaries if we have them at all, but it was not my favorite work and I didn’t find it especially impactful. At least OpenHistoricalMap can claim to have more comprehensive coverage of Alaska’s census areas over time than any other online source (as far as I know) and could eventually achieve that for CDPs too. In general, OHM’s more research-oriented approach is a better fit for boundary mapping compared to OSM’s surveying ethos.
Yes and no. Among the U.S. community, there has been broad agreement since the late 2000s that a) census boundaries aren’t administrative boundaries and b) they aren’t a priority for the project. We did not reach agreement on keeping them all or removing them all. The compromise has been to selectively preserve CDP boundaries as boundary=census.
Some mappers felt very strongly that the CDP boundaries in their areas should be preserved in OSM, either because of local relevance or because they were confident in their ability to maintain and use their local subset of CDP coverage. Even the most outspoken opponents of CDP boundaries were willing to make some exceptions for places like Maryland or the Navajo Nation where these boundaries actually matter, as long as they got retagged.
Shunting the CDP boundaries over to boundary=census has made them more niche, gotten them out of the way of most mappers and users. At the same time, they’ve offered geocoders slightly more context about unincorporated places, for better or worse. I think it would be worth revisiting whether the claims about maintaining CDP coverage have proven out. Some of the folks involved with these early discussions are still around, but others have fallen away. Maybe our CDPs have decayed to the point where we should toss them out and require a consensus before reintroducing any. But I think this is unlikely to be the case everywhere, partly because of Bethesda, Maryland, and partly because of active efforts to refine these boundaries.
Amid all the place classification discussions over the years, I don’t recall ever seeing the Alaska census areas being used to justify the inclusion of CDPs. After all, the census areas are already inherently safely out of the way of most mappers. As you’ve pointed out on several occasions, Alaska is a bit of a unique situation overall.