According to Benji, MUA3 is doing significantly better then his expectations, looking to be at least the third best launch for a Switch game.
https://twitter.com/BenjiSales/status/1153013394905190412?s=19
Nintendo definitively made a good in not only reviving this, but securing it as an exclusive. Having it released just a couple months after Endgame, a couple of weeks after Far From Home, and the day before the big Phase 4 for the MCU reveal was a smart move.