It could be interesting for regulators to see if anyone "miraculously" managed to make a lot of money from/during this incident, because some people do have the resources to pull something like this off and make a profit from it. But I think it's rather unlikely.
Aside from that, I seriously doubt that just disruption of AT&T services was the objective here. Considering that this appears to have been a rather serious explosion, I guess the intent was more likely destruction rather than disruption.
With the amount of 5G nut jobs running around these days, I suspect that it is far more likely that somebody just seriously underestimated what it takes to bring down a building like this one.
But I guess that time will tell (more). I'm just speculating of course.