Apple messaging is super annoying. I use Android phone but also have an iPad. Whenever I chat with someone on iPhone, is suddenly decides to route all messages via iMessage instead of SMS and I do not see them on my phone. You have to disable iMessage in iPad to avoid this.
I don’t see how this is a problem. If you want to use an inferior method then it should be opt out (like you are doing) instead of the other way around.
Also, changing the mode of communication withot asking or informing users sounds like a bad idea. I send you SMS from my phone. You see it in your iMessage and type a reply and it goes back to my iPad.