Not Metroid specific per say but here are titles for anyone looking to get their Metroidvania fix on Switch in the mean time:
Hollow Knight
Ori and the Blind Forest
Bloodstained:ROTN (Switch version soon to be patched to sort out the issues)
Bloodstained:COTM
Castlevania Collection
Steam World Dig 1+2
Dead Cells
Upcoming in Jan 2020 Hollow Knight Silk Song will be one to look out for.