i dont think he's plot fodder, but i do agree we havent seen the true villain yet....
you know, i dont think we will get a 'true villain' in the tourney plot....i think the 'villain' is the xenos and them wanting to erase all but 5 universes just cause.....i think the grand priest is gonna use the tourney to show them that these universes have potential and shouldnt be erased...
also, think they will make the tourney a reg thing to keep them entertained, maybe not 10 people per team, but at least 3-5.....the 4 exempt universes would be entered too, so we'd get to see how strong fighters from their universes really are....
in the end: i think the tourney gonna end in a draw between jiren and goku....by that i mean they will be the only 2 left in the ring when the timer runs out....they both gonna get a wish, goku will go first and wish all the universes back, which will surprise jiren...who'll then wish to fight/train with goku out of respect he's gained for him....