Well considering that at every home game at the symbolic time of 17 minutes and 14 seconds the crowd chant for "independencia" I think the answer is yes...
I'm not sure that you're correct about that. From what I can gather Barcelona fans are very entrenched in their Catalan identity.
https://www.si.com/soccer/2012/10/29/barcelona-catalan-identity-ap
FC Barcelona have a long historical tradition of coming into conflict with the more repressive elements of the Spanish establishment going back to before the Spanish Civil war. Their ground was closed for six months in 1925 after their supporters jeered the Spanish national anthem. During the...