Honestly, I don’t think that this is an unpopular feature request. It seems to me that getting content updates is pretty integral to the purpose of AnkiHub - at least it was for me, and that is why I chose AnkiHub over downloading older, free decks from Reddit, etc.
I strongly believe that being able to customize cards to better suit one’s learning while also getting content updates is a best-of-both-worlds situation and therefore is worth taking the time to implement. Although anecdotal, I know several people who pay for AnkiHub yet avoid syncing so that they don’t overwrite their local changes. I know they could use the Protect tags, but that’s not really my point; my point is that I don’t think anyone should have to choose between customizing cards vs. getting content updates.
The following posts are all related to the issue of protected tags vs. content updates in some way, for what it’s worth:
Cards w/ Protected Tags Updated (@shmuelsash, @bradydjohnson, @Jwill)
Protecting Extra and Text Except for Errata? (@jfrankel, @TheAnKing)
Update the Text field but protect custom clozes (@Carrotid)
Warning, this Flash cards ("Text/Extra") that you protected has been update, please click to view (@prader_willi, @dollajas)
Preview current version of note quickly (@MightyBooman)
View on Ankihub Shortcut Key (@TheTommyLlama)
Sync Individual Card (@ jakub.f)
Sorry in advance for tagging everyone, but I just want to centralize the conversation here, so that it can be more productive. I genuinely think that this functionality is a core piece of why/whether people choose to use AnkiHub, that it would very positively contribute to the user experience, and that it would increase the appeal of AnkiHub to new potential users.