I think they mean it more as it’s not only gonna be Google but Apple who are going to be shoving RCS down their throats of people wether they want it or not by shipping it as default.
On the other hand, the era when corporations cared even the tiniest bit for open standards in instant messaging was gone long ago. Now all instant messaging is a complete mess, we users have to deal with a myriad of apps and protocols that in the end are doing the same thing for the sake of “privacy”, and RCS will not fix that. Nor Signal, truth be told.
I yearn the glory days of multi-protocol IM apps like Pidgin and Trident on Android (though +IM seems to still be a thing) - when you could use whatever you wanted without “missing features” or risking to be banned.