The FCC has given mobile operators more power surrounding SMS, and in doing so have actually classified the service as different from texting applications and services like GoogleVoice, WhatsApp, Telegram, Signal and all the rest of the alternatives, including Apple's own iMessage. I say this because they went to great lengths to not include the Google backed RCS.
In the past, during the VoIP heydays, we used to use the "duck test." That was, if it worked like a phone, and provided service like a phone, it was a phone service. Clearly the FCC is not applying that test to messaging, at this time. That move has some interesting implications.
For starters, if only the mobile operators are classified as information services, then they are not given FCC oversight. But there's no saying that the MNO's can't begin to treat the other services differently, including how they use the SMS system, and pay (or don't pay) for it. For example, if Verizon wanted to stop all SIGNAL or TELEGRAM traffic on their network, they could in theory, the same way they could block porn (if they wanted to) from traversing the wirelesss network.
In the case of this decision, it's more a case of what wasn't included than what was included. Only time will tell if the MNO's start to block traffic or degrade their timely delivery.