Note though that the one reported here still compiles in Dotty (at this moment in time).
That one throws conversion to Unit in the mix. It should be easy to exclude on top of the rules we have.
Feature request ticket to deprecate or at minimum offer a lint: Lint or deprecate auto-tupling (like Scala 2's `-Xlint:adapted-args`) · lampepfl/dotty · Discussion #19255 · GitHub