Social Media is the new battleground for setting majors agendas. We've had US Presidents and EU Referendums decided by them in recent years.This is an extremely online take. In terms of buying a club for the purposes of sportswashings, having someone in your corner for twitter/forum slapfights isn't a main reason. I don't know that it's a reason at all, actually.
The whole point is generating broader societal acceptance and positive opinions through success and investment in the region; caring about online wars doesn't even register.
Investment in the region won't be a factor to anybody outside of the catchment area. That's far too parochial a reason for Saudi Arabia to invest in something from half a world away.