Google and company can go fuck themselves on this one, and I'm usually the first one to bash on Apple for selling overpriced status symbols.
I'm frankly amazed at how much importance Google gives iMessage, when it's not the number 1 messaging app anywhere in the world. Hell, even if you assume Apple halved its report of monthly active users in Europe, that's 90 million people in Europe. Significant, but less than 25% of the total population of the EU
Outside USA and Canada, you'll be hard pressed to find people who give a damn about iMessage, because most are using a different, cross compatible app anyway, like Whatsapp or Telegram, even across most European countries.