I wish Metroid all the succes, but I cannot see 1 in 20 Switch owners buying it. Typical first person games don't do well on Nintendo systems. Golden Eye was the odd one out on the N64.
Metroid Prime Remaster is one of the few first party games that did not have the Switch effect to sell more than the original release.
If Prime4 can reach 3 million, I think Nintendo will be very happy about it.