Let's be honest : Eula waited this long because she's not a great unit to begin with. So, character banners aren't looking that good, and don't get me started on the weapon banner.
spoiler
But speaking about skins : Kaeya is getting one too.
So, it would be nice surprise for him to have a banner rate-up as well. I'm sure a lot of people would like to have his constellations.