The linked article links the issue to net neutrality, and whether or not net neutrality is related seems to be a key point under dispute. If you’re going to claim it has nothing to do with net neutrality, then failing to make an argument for this position is begging the question.
“They already did this” is not a very good argument, since it’s perfectly logically possible that they were already violating net neutrality principles or rules.
The headline is confusing, though, and doesn’t do a good job of presenting the linked article.
ETA:
The throttling was done under a provision in the rule for “reasonable network management”, and was supposed to only apply in times of high network congestion, though actually Verizon and other carriers were flouting the rule by advertising plans that throttled after a threshold had been reached - i.e. the throttling was built into the plans as part of their rate structure, not used as a mechanism for managing network congestion.
Why not just cap data usage entirely instead of throttling? Presumably because they like to throw “unlimited” into their advertising.
So net neutrality is related, but only because telcos like to advertise “unlimited data” on plans that are actually limited.
