I'd imagine that to be short lived. IPv6 having such a huge address spaces means the IP reputations are even more worthless than IPv4 so eventually the bots would use it too, and if the ratio of bots to real users become too high sites may refuse IPv6 traffic altogether.
It’s a little different though in that rather than an IP having a bad reputation, it’s usually a /64. That’s how I have seen IPv6 reputation managed since it’s a common network slice & NAT is not really used anymore.
Ooof that's an ugly thought. But I think "refuse IPv6 traffic altogether" is not possible for any consumer site. Per the article, there's 40% adoption of IPv6 now and it's only growing. Major parts of the world rely on IPv6 working right. I guess sites could go IPv4-only but given how many other problems there are with IP reputations, that'd be awfully dumb.