(Can't read the article from my current location) But will the games be downloadable directly from Humble Bundle, or am I just buying a key to redeem on the Epic Game Store (which is the way most HB game purchases work)? If it's the latter, then it is still exclusive.
https://www.ign.com/articles/2019/03/20/epic-is-bringing-its...
So while it's not 100% the same, it's progression far faster than Steam did when Valve pissed the gaming community off by forcing HL2 players to install Steam.