It wouldn't matter if it was Google, Dropbox, OneDrive, etc. It can happen with any service provider. Always keep local copies in a locally editable format.
This is true, but I think there's also room for "Google is more willing to rely on algorithmic termination than other providers, so be extra careful!" to be true as well.
Where are you getting that from though? I've seen the same thing happen with Dropbox more personally but I'm not going to make that claim based on my bias.