So, as a moderator for !manga@ani.social, I have been trying to keep tabs on how this has been developing over on reddit (especially /r/manga).
I believe that if a publisher were to request content or posts to be removed, it would most likely be directed to the instance admin. In my community's case, that would be @hitagi@ani.social. It would then be up to them whether to or how to remove the content. If it isn't a formal DMCA or if they are in a jurisdiction not bound by the DMCA, then they could always choose not to take action. If they did decide to remove the content, then the next decision facing them would be how to remove it.
One option would be to "remove" it (no different than a community moderator removing things like spam). This action would federate out to other lemmy servers and remove it there as well. The other option that is available to instance admins is to "purge" it. This removes the content from the local server, but does not federate that removal out to other instances. So, the offending content would still be available to the rest of the fediverse since it was federated out and the publisher would have to go play whack-a-mole with every instance out there. The purge option would definitely be the malicious compliance route.

Source for people that don't know is Tomo-chan is a Girl!. This is a fan-colored version of chapter 907 (each chapter is just one page).
Wow, did that person fan-coloring the whole series make it this far already?
Edit: this fan-coloring was done by somebody else. The person I was thinking of is /u/fukai20 who posted a while back that they have been on a bit of a hiatus.