This is the best guarantee any company ever gives.
For smaller companies if something becomes too expensive or hard, they just go out of business. For larger companies, they have to draw the line somewhere. You won't get stronger guarantees from anyone, that would be insane.
Google definitely has a history of turning down free services when they're proving unprofitable, but that's only free services. There's no history of Google turning down paid services without good notice that I know of.
For smaller companies if something becomes too expensive or hard, they just go out of business. For larger companies, they have to draw the line somewhere. You won't get stronger guarantees from anyone, that would be insane.
Google definitely has a history of turning down free services when they're proving unprofitable, but that's only free services. There's no history of Google turning down paid services without good notice that I know of.