Incorrect. If multiple services interoperate with each other, that does not mean that one service can vacuum up the entire data on that network. As an analogy, Gmail servers cannot touch emails that are stored on Outlook and have never been addressed to a Gmail recipient. And if your position is that Google gets access to traffic flowing on a heterogeneous group of iOS and Android users simply because of RCS, that is again incorrect. RCS does not enable any new insidious capabilities that Google may not already have by the virtue of building Android.

RCS will have no effect on iMessage whatsoever. Messages between a homogeneous group of iOS users has no reason to touch Google owned (or other) RCS servers. And for Android users, RCS is a meaningful upgrade from traditional SMS.