I mean... not only Activision.
Almost everyone that makes collections or remakes sell the game at a lesser price. Not only this gen but also during the previous gen. I mean, you could find a lot of HD Collections of franchises for 40 bucks, including 2-3 games. The Metal Gear Solid Collection, Tomb Raider Collection, ICO & Shadow of the Colossus HD, God of War Collection, Devil May Cry 1-3, and more examples.
Then you have other examples, such as the remaster of Okami. I literally bought the game for 20€ when it came out on PS4. Or big ass remakes such as the Shadow of the Colossus PS4 for 40, being essentially 1:1 to the original, or Resident Evil 2 and Final Fantasy VII Remake, which came out at 60 bucks but as a high budget games, changes and additions.
In the end, the Mario Collection being 60 dollars is the least of it's problems in comparison to other examples.
TL:DR Most companies handle remasters/remakers like 20 times better than Nintendo, with games such as Metroid: Samus Returns being the exception.
GG TALK??? I'M COMING
I don't know if it's hella slept on, but not gonna lie, I felt that an ArcSys character seemed somewhat more likely after the spirits they added, which were included not that long after they announced Pass 2, by the way.
Sol or Ragna are still unlikely in my opinion, but definitely not impossible.