I really wouldn’t know. In this context I assume it means it is not deployed like traditional mobile networks are. The missing components being the hardware side like putting up towers etc.

They said Google has a monopoly using their own Jio virtual carrier. They never said Jio doesn’t support RCS.

Yep it’s definitely a thing. For those saying you’re not seeing it, that’s because you’re not blocking it. I use multiple layers of ad blocking but my unlock is set to block third party scripts and frames by default.