7.1 Discontinuance of Services. Subject to Section 7.2, Google may discontinue any Services or any portion or feature for any reason at any time without liability to Customer.
7.2 Deprecation Policy. Google will announce if it intends to discontinue or make backwards incompatible changes to the Services specified at the URL in the next sentence. Google will use commercially reasonable efforts to continue to operate those Services versions and features identified at https://cloud.google.com/terms/deprecation without these changes for at least one year after that announcement, unless (as Google determines in its reasonable good faith judgment)
So technically they can do it, though their enterprise customers likely have stronger agreements that require at least X time (probably 1 year) notice