Super Mario Maker is definitely the most important MARIO game to either make a sequel to or port over at this point, but lord will the absence of Miiverse be obvious. I'd love to see Mario Maker on a healthy, populated system.
I'll confess to growing impatient with the lack of anything resembling Miiverse on the Switch... why discontinue that service if you had nothing to replace it? Miiverse was brilliant, all it needed was a rebranding and some tinkering... Nintendo can be very frustrating at times heh
As for the rest, that strategy makes sense. Third party, Wii U ports and some first party from franchises that are popular but not necessarily huge sellers (Kirby, Yoshi) is probably all they need for this year. The eventual Pokémon title alone is sufficient to revitalize the system should it begin to experience a lull at some point.