While Smash Bros. Ultimate is bringing back every single fighter that's ever appeared on the roster, it's not going to be the same case for stages. At E3 2018, Nintendo stated that while many stages will indeed return, there will be some that don't make the cut. No specifics were given on which stages won't return.
QUELLE und TEXT: https://gonintendo.com/stories/312255-smash-bros-ultimate-won-t-bring-back-every-smash-bros-stage

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