My main thought stems from this. We only ever started considering Ryu because of a leak. Nothing more. He is so high on the list of "possibles" because of said leak. I dont remember him on polls, I dont remember him in standard conversation until that leak. When I also look at the characters we have.
Joker - Sega/Atlus
Banjo/Steve - Microsoft
Terry - SNK
MinMin/Byleth/Plant - Nintendo
Hero - Square
Now. Conjecture time.
I personally think Joker was picked because P5 was big and Sega/Atlus wanted some sweet advertising. Likewise, I see Hero as a packaged deal with cloud. For Microsoft, given the fan demand for Banjo, I see they doing the 2 for 1 deal with Banjo/Steve. Nintendo owns its characters, with the main 2 we have being promos. That leaves Terry. I say that is Sakurai Bias.
When we look at FP1, we have Joker/Byleth which has some, but not lots of support. We look at Hero and Banjo, whom had TONS of support. and we see Terry, who had Sakurai support. In FP2. we have MinMin and Steve, which had Nintendo support.
and that is where I look at it. Nintendo support. What characters did nintendo see fit. Last 3 have felt like Nintendo mandates (not complaining. I like MinMin and Steve)., I personally cannot see Ryu as a nintendo mandate. I just cannot. He is the same level as Arthur from Ghost and Goblins, or Joe from Shinobi. From hard games that people played a million times because of jank. He is no more likely then say the Contra duo.