It's not just Twilio, you would have experienced this with nearly every SMS API provider. Across the different vendors I work with, I received numerous emails from each one advising me to come into compliance or risk my messages being rejected.
https://help.salesmessage.com/en/articles/6650461-changes-to...
https://www.telgorithm.com/news/10dlc-registration-required/
https://support.referrizer.com/support/solutions/articles/10...
From what I can tell, the telcos aren't performing any enforcement, even tho the deadlines and extensions are long past. Not to say they won't but the endeavor seems to have a stall vibe going on.
Some of that might be related to having major mass-campaign requirements placed on small biz who occasionally send a handful of texts (often non-sales) from their workstation phone apps.
At least I hope this is why it has stalled. Sending a few texts during a customer service session shouldn't be regulated as if it were a blast of 1M SMS ads.
New telco industry texting requirements came into play. In short, US biz are required to register with The Campaign Registry and pay regular fees if they want to do any (as in 1+) software text comms.
It can be onerous for not-large biz. Twillo took point early-on (inserting themselves into the administration, IIRC) and Twillo then got a lot of heat from their users - even tho the requirements originated from the telcos.
It's a shame as I think there are some legit non-spam use cases for SMS as a messaging platform, but considering you now seemingly need to pay, fill out a bunch of annoying/buggy forms, and wait for days to who-knows-how-long before sending a single message in development, I'd say it's been pretty well destroyed as anything a dev would ever play around with. Who's going to do all that before writing a line of code?
That bad UX is being supplied by The Campaign Registry org.
I do recall Twillo performing TCR's tasks in the beginning (applications, registration, etc) but only until TCR was spun up. It's all on TCR now.