Personally I think adding him in as a sticker pack is a cute way to embrace the joke and keep him around for the more nostalgically-inclined, in a nonintrusive way. The "brand police" clearly don't understand that people like to see a human side of the soulless corporations they buy software from.
Did the research. Even if you got a copy of the github repository, all the actual clippy stickers were downloaded on the fly from a series of called out URLs in a config file following this pattern: https://msteamsclippy.azureedge.net/150/*.gif
That domain is NXDOMAIN now.
I wanted to send him into my company's Teams chat today and was disappointed I wasn't able to find him.
I'm willing to bet that Teams' sticker feature saw a few % of increase in interaction. It was my first time opening it.
The Office org at Microsoft can be way too serious sometimes.