The prohibition against blocking, etc., any lawful content or applications found in both the 2010 and 2015 regs is exactly about censorship, whether or not it is ideological.
The link you provided talks about censorship on forums etc. That happens on Facebook, Twitter, Reddit, etc. every day. ISPs no longer own most of the social media, but I'm not sure how the same kind of censorship is ok now (in fact, Congress just severely criticized Facebook and Twitter for doing not enough of it and allowing Russians to publish their opinions about US matters on these sites) but exactly the same censorship was not ok then? Cases of ISPs refusing hosting and other similar services are known and widely lauded. Of course, that was not because it was about censorship, but because Nazis were the ones being censored, but censorship as a principle has been accepted, and the question now is only who you can censor. And as you can know, there's no shortage of people who would declare everybody who doesn't agree with them literally Hitler and demand to censor them. Either we accept this is ok and the competition will take care of it, or we say the state must intervene and stop it - but we can't say both depending on how the company doing it is called.
Yes, the people for whom edge provider censorship is a concern frequently do exactly that, and complain that regulatory intervention is necessary.
It's true that the people concerned about edge provider censorship and those concerned about access provider censorship are often different people.
> Except there's no single instance of such censorship I've heard so far happening before 2015
https://cs.stanford.edu/people/eroberts/cs181/projects/1998-...
> and NN not being about censorship at all.
The prohibition against blocking, etc., any lawful content or applications found in both the 2010 and 2015 regs is exactly about censorship, whether or not it is ideological.