Can't say I knew what I was doing but after some googling a cabal v1-install tidal solved the problem. I still have no console in Atom but Emacs and Tidal are working together again.
@jwaldmann, by the way, have you ever noticed Emacs getting slow and laggy while running tidal-mode? (I know, this can have multiple reasons - and it wasn't this one - but maybe there is an obvious one.)