If there is a consensus that arrows are better enough that lambdas, and arrows happen, lambdas will be considered 'old' and automated converters such as pyupgrade will be quick to replace lambdas (and people publishing libraries will have to wait until the EOL of the older versions of Python before being able to run it).

And if, otherwise, there is no such consensus, the change will never happen.

Same as u"xxx" versus Unicode("xxx"), x**y vs pow(x, y), x @ y vs. matmul(x, y), etc.

  S.