Biker Taker question

I’ve always wondered about Undertaker’s return as Biker Taker in 2000, as I wasn’t watching at the time. I understand it’s the attitude era, and evil taker was already taking steps into a more “human role”, but the crowd immediately pops at Judgment Day, as if this was his persona all along. I would’ve expected more of a WTF vibe. Were there rumors that this is what’s coming and therefore everybody was ready for it?

Yup. I think they even had a series of videos beforehand teasing the change. Even then, by late 99 the "evil Undertaker" gimmick was morphing into grumpy redneck Undertaker on screen, so it wasn't even a big stretch.