shoichi on 15 June 2017
I think they announced this because they wanted to announce Metroid: Samus Returns.
Think of all the backlash if Nintendo said "Hey here is Metroid: Samus Returns a remake of Metroid 2" then goes on in the Spotlight without announcing Metroid Prime 4. Guarantee people would be like "Where's my Metroid Prime 4, I want the Prime series", " why isnt Switch getting a Metroid", etc.
Like the backlash when Pokémon US/UM got announced with nothing about the Switch except Pokken, which is probably why they announced what is likely the next generation for the Switch in the Spotlight.
