That phrasing caught my eye too; no mention of Switch hardware being playable on the successor. I’m just being overly cautious for now but given how eager Sony and Microsoft seem to be to drop physical games we can’t assume cartridges will be supported just because they say that Switch software will be playable.
Metroid Prime 2 is the only main Metroid game I’ve still not completed. The whole light/dark mechanic was just so joyless and punishing. I’ll still be buying this and giving it another go; a few quality of life tweaks and this could be enjoyable.