Now, I agree with most of what you said.
Google doesn't want people using their cloud platform 24/7 for non-cloud related things.
Who knows what's google's real intentions. We've got terms and conditions to specifically and accurately make sure the intentions are satisfied.
In my opinion, and by consumer's rights any unclarity in such circumstances should be considered towards consumer's benefit, at least until the terms are clarified. However if there is a specified time offer, the terms can't be changed without both sides consent before the agreed time has expired - That would be the case of most commercial legally-binding offers.
I don't want to go on any warpath over this method. All I'm saying is that as for now it is fine to use it and doesn't breach terms and conditions. Shall google ever relate to this specific use of their service - I will be the first one to post this information as an update for the guide.
Currently I simply appreciate google's generosity and gladly and smartly contribute to research that really matters.
Also @roboticmind , you're the first person to approach this controversial subject with logic, manners and intelligence. So I'm happy to upvote your comment.