Is there a reason why any future syntax changes cannot be handled using transpilers in the same way it's worked for the JavaScript community? Such transpilers do exist for Python, but they never really saw much use, is it because 3to2 came along too late, and for a long time we only had the option of 2to3?

ie once future syntax develops, start using it immediately using a transpiler, and have builds that target as many versions as you care to support.