Comcast (an ISP) purchased NBC Universal in 2013, ATT (also an IPS) purchased Time Warner in 2018. But that was it, and both of those deals ended up being bad for the ISPs, with ATT already divested of Time Warner and Comcast trying to get rid of NBC Universal or whatever is left of it.

I do not think blocking websites was a goal in either of those mergers, they were just trying to become big like Apple/Amazon/etc and not just be a dumb pipe like ISPs should be.

At least in theory the blocking in EU has to go through a judge.

Blocking itself is ofcourse not at all controversial in Europe. Aside from some free speech maximalists people have no problem with shutting down criminal operations.