> These the same residential providers that people complain cut them off for torrenting?
Assume that you are in the shoes of Anubis users. Do you have a reasonable legal budget? No? From experience, most ISPs would not really respond unless either their network has become unstable as a consequence, or if legal advised them to cooperate. Realistically, at the time that they read your plea the activity has already died off (on their network), and the best that they can do is to give you the netflows to do your investigation.
> You think they wouldn't cut off customers who DDoS?
This is not your typical DDoS where the stability of the network links are affected (this is at the ISP level, not specifically your server), this is a very asymmetrical one where it seemingly blends out as normal browsing. Unless you have a reasonable legal budget, they would suggest to use RTBH (https://www.cisco.com/c/dam/en_us/about/security/intelligenc...) or a commercial filtering solution if need be. This even assumes that they're symphatetic to your pleas, at worst case you're dealing with state-backed ISPs that are known not to respond at all.
