I agree, but for the record, if Google wanted to sue, they wouldn’t be completely out of luck. They could make claims under the Lanham Act §1125(a), state unfair competition laws, or other fraud-adjacent laws. But they would have to prove that Microsoft was deceiving customers, and it would be a lot harder without an actual case of trademark infringement.

They could also try to claim trademark infringement based on the fact that Microsoft is hijacking searches for the keyword “google”. Courts have previously rejected trademark claims when a company takes out search ads using its competitor’s name as a keyword, but Google could argue that what Microsoft is doing here is more deceptive than that.

(IANAL and have only passing familiarity, but I’m fairly confident in the above.)