Apple promotes itself as being the most focused company on security so I think it's safe to assume they will work with the GSMA to add a layer of encryption to the universal profile. I believe it has already been reported that is the plan. If that happens Google will be forced to switch to that or the two will only communicate unencrypted RCS messages between them.This is really the best outcome. Better texting for all but Apple isn’t caving to Google‘s proprietary and spotty encryption. I’m excited!
No one really knows how this is all going to turn out. Regardless RCS will offer a much better texting experience between an iPhone and an Android phone.