Nothing serious, I guess. Even if RN sees torpedo bombers as its main force and manages to get one or two carriers to Singapore, old Swordfishes are too weak against IJN planes. Force Z ships will be sunk, no matter what (theoretically speaking, British biplanes may sink a Japanese cruiser, but their carriers will be sunk meanwhile). Maybe, the Admiralty will refuse to send capital ships to the Far East? If so, then many of British sailors will survive 1941. Singapore, though, will fall according to the OTL schedule. That's all.