Every time someone hijacks a Google announcement thread doom crying about potential shutdown it gets under my skin, especially in this case when these “arguments” are so intellectually bankrupt.
If you are suggesting that GCE or the whole Google Could Platform endeavour is in anyway similar to any of the appendage service or features Google shelved over the years, then that calls into question the adequacy of your critical faculties or any vested interest you may have in undermining their efforts, and leading with a disclaimer doesn't take that option off the table.
There is also the argument that when Google deprecates something you are more likely to hear about it which creates the false impression that they depreciate more stuff or more important stuff than others.
Disclaimer: I too work for Google.
2nd Disclaimer: No I don't.