40-42 will never be too big.
I won't say those extreme things like 50 or even 55 will stay forever but 42-43 will never be too big. This is evolution. Int 1940 they were 32-33 in the 1950's - 1960's 34-35 was normal till they 1990's 36 till 39 were the standard. Today they reached till 43.
Everything under 44 will always be good, I do'nt think they will be bigger in 2030 because our wrist has limits but a 42 mm does not look stupid on any wrist. 50mm is another story, this is a fad