Except I explained why that's not true. Both Altus and Square Enix got their start on Nintendo platforms. Final Fantasy has an especially rich history with Nintendo, even having the first 6 mainline games. If you then go into ports, remasters, and exclusives on Nintendo platforms, the list is super expansive. Cloud is inarguably the most popular and most recognized Final Fantasy protagonist to the point that Cloud is argued to be the best character to not only represent Square Enix but JRPGs period.
Again, there are roughly 50 Final Fantasy games on Nintendo platforms alone, not even counting Square Enix games altogether:
https://nintendo.fandom.com/wiki/Final_Fantasy_(series)
Like I posted earlier, Altus has a relationship with Nintendo that goes back to the 80's. Their first ever game was on the NES and it was Megami Tensei, their signature series which Persona ultimately came from. Why have Jack Frost when Persona 5 was one of the company's best sellers, won awards all over the world, has multiple spin-offs, has inspired several Joker cameos even before Smash, etc. Like in the Cloud example, it just makes sense to go with Joker, just as it makes sense to go with Cloud instead of Moogle.