Most Latinos just wanted to make fun of Argentina and "support" Spain because of how unbearable it would be if Argentina won again. Most Right-Wing Argentinians like Milei hate football and probably doesn't even give a shit that Argentina lost. It doesn't help that out of nowhere Israel comes to support Argentina because they are buddies with Milel, most people in LatAm fucking hate Israel. Also a bunch of racist Argetinian assholes were attacking random African-American, African and Afro-Latino people by shouting slurs and dumb shit, they even attacked the Streamer Ishowspeed (it wasn't dumb sport thing, these people were just being racist).

Doesn't feel very organic but I can't guess who would be pushing it, maybe Britain seizing a moment because Argentina being hated is beneficial to getting sympathy over the falklands?

Afaik only Europeans (specially British People) give a shit about the Islands. Most of the Global South usually side with Argentina in this issue.