If Alan Turing was never to break The Enigma Code would the allied forces have still won or would Nazi Germany 'win' the war?
So this and questions in general about "The Immitation Game" have come up from time to time.
https://www.reddit.com/r/AskHistorians/comments/3cf0es/how_accurate_is_the_imitation_game/
https://www.reddit.com/r/AskHistorians/comments/2recvz/how_historically_accurate_is_the_film_the/
The general consensus is that while he and everyone who worked in Allied SIGINT did important work to inform decision making it was in no real sense a sine qua non effort. The underlying economic imbalance between the Allies and Axis are in many ways too large to ignore in any context. Especially in relation to temporary and fleeting intelligence breakthroughs.
It would have taken longer and been more bloody, but the advanced depth charge, light frigate and destroyer escort, and escort carrier were the true tools to securing the Atlantic regardless of the intel situation.