Small tangent, but I feel like it is a good time to drop the term "net neutrality", which covers way too much ground. In the past in political discussions, the term "violation of net neutrality" was used to protest multiple different issues:
* Traffic shaping (e.g. slowing down Bittorrent traffic)
* Traffic fast lanes (pay for priority access to some content providers)
* Selective zero-rating (exclude some providers from counting towards a traffic limit)
* Artificial peering restriction (what Telekom is doing, usually via forcing content providers into paid peering agreements)
I think people should start using more specific terms that are understandable for non-technical people, because otherwise the discussion becomes confused, which helps the providers.
Lots of semi-technical people think that "violating net neutrality" refers to traffic fast lanes, because the last time this discussion entered the public was when the US social media was in uproar about FCC rules 10 years ago.
What Telekom is doing looks similar to the outside (some content providers are fast, some are not), but they can just deflect by saying that they do not intentionally throttle traffic, which is pretty much true, as they hit their physical bottlenecks. If you are knowledgable enough as a lawmaker to press them on the peering issue, they could argue that forcing peering would force them to pay rent at Internet Exchanges, just so other providers have good access. Where they also kind of have a point.
And even lots of technical people have no clue about peering, transit etc. and treat their uplink as a blackbox, a cloud in their network chart where the Internet comes out.
For the Telekom case, we would need a different legislation, for example make paid peering agreements between providers illegal or at least regulated, which would then be an incentive to be generally well-connected (free mutual peering is usually considered a win-win scenario unless you are Deutsche Telekom and can use your market power to bully other market participants into another form of rent extraction). And that means that lawmakers and the public need to understand first the specific problem we are fighting.