A lot of the Play-test material feedback has not been shared as of late. I did some digging on their website looking for articles regarding UA survey feedback, and from what I saw they don't appear to publish the results of the various UA surveys. Right now a UA comes out once every two to three weeks with a survey for the previous UA article's contents dropping inside the current UA article. Digging back to about to three years worth of UA material I see the same format with the surveys becoming available in the next article but none of the articles share their results or WoTC's thoughts on the feedback they received.
There was a small exception regarding the Mystic and Artificer classes being place on DMSGuild and the announcement of further dedication to improve these classes for full release. But that article doesn't discuss the feedback in itself rather discussing how overwhelmingly positive it has been and as such they will be increasing efforts on their development. They did mention that the classes would see release in the Adventurer's League once they have refined them further before their official release and as such the removale of the Archivist could've been from table feedback they received in the league or from DMSGuild
The general D&D feedback surveys they release every year used to get feedback articles discussing the results and player concerns. However, it appears that they've stopped writing articles regarding the results of these surveys instead taking them internally. The last article discussing results of these surveys goes back to March of 2016. And unfortunately I couldn't find an article since discussing the feedback they've received in the recent years, It appears they've elected to not share these results which means there wouldn't really be many ways to figure out how well received a variety of concepts were.