I'm from Spain. There's is lots of racism in my country. However, the stereotype of black people and fried chicken doesn't exist in my country, that's an American thing. I believe this is just an unfortunate coincidence.
Likewise, there are things that in Spain would be considered racist that aren't in other places. I mean, I recently learned that now in America the Ok sign is a Nazi thing. I looked up the history of the fried chicken thing and it originates in America, we don't even have a tradition of fried chicken.
The joke they are making is that this player commited a penalty this weekend which was very controversial because he wasn't facing the ball but had his hand high in the air, and they are implying it was to get some of their chicken. I have no doubt they'd have made the same joke if it was a white player, it's not like we aren't constantly making jokes about Hazard going to MacDonald's. It was unfortunate for sure, and they should take it down, but I don't think it's fair to blame a Spaniard community manager for not knowing about a racist American stereotype, believe it or not the US is not the centre or the world.