Requiring Server Name Indication (SNI) extension is quite significant as if I understand correctly then this blocks Windows XP to access any of the Google services with any version of Internet Explorer.
I'm not sure it's all that significant - it's been inevitable for years, and Chrome and Firefox will still work.
Running a 14-year-old browser on a 14-year-old OS and complaining about support being dropped is like running a computer with 256MB of RAM and complaining you can't play the latest games :)
They are not dropping support immediately. They are providing advice so that future TLS clients (particularly embedded) will not have problems when support for things like TLS 1.0 is dropped likely years in the future.
