How much advance notice did they give when they were shutting down that email service? I bet it was like eight months or more. Things change, you have to deal with it sometimes. Seems kinda normal.
People don't like to rewrite infrastructure code just b/c the provider decided it's not worth it anymore. When you sign up you consider the whole ecosystem not individual services. The cloud platform is marketed as reliable and rock solid that you can trust. It may be the case with AWS but on Google you should expect experimental, cheap and a high risk to get broken or even deprecated all together. It behaves like a start-up with customers paying for experiments. It's OK for some use cases but you should be aware of that.