Well, since ISPs are now free to sell / monetize consumer traffic data [0], this makes some sense. They are pretty desperate for ways to be something more than a dumb pipe for other's content.
Absence (with the threat of regulation) is a very different state than an explicit ban on regulation (via the CRA) and what amounts to a governmental endorsement of their move into ad tech.
You're correct that the rules never went into effect, but they also had no reason to invest in ad tech with the (increasingly probable) regulation looming in the future.