It remains to be seen whether Profiles are an RCS feature or something that Google (Messages) is managing and hosting itself.
This misconception that RCS isn't just Google in a big hat is strong.
If your using RCS it is highly probable you or one of your contacts are being provided with RCS through Jibe.
Jibe is Google's proprietary RCS backend. Carriers aren't implementing RCS so Google does it for them. RCS isn't a proper open standard, it's Google trying to jam it's messaging service into your life through the backdoor.
Developers can't make custom frontends for RCS because Google won't let them. Only Google and device manufacturers can.
They are trying to force apple into this system as well. They hope to get iMessage to support it. So they'll have their messaging system embedded into every Android or iPhone.
The worst part is it barely works. I'll get more unable to deliver over RCS than I've ever seen on Signal, Telegram and WhatsApp. As soon I switch back to SMS it delivers straight away. The fact it doesn't switch automatically further frustrates me because it'll leave messages hanging, when you expect the text messaging app to send texts.