Barcelona has already secured the title, and Bilbao has already secured a place in the UCL. I think both teams have no motivation in that match. Barcelona will probably field their young players or even Barcelona B players. But on the other hand Bilbao also has no reason to play with high intensity. I predict Barcelona will still play most of their main squad but they will play without any pressure. Maybe Flick will make some substitutions to give the bench players a chance. The same thing seems to be done by Bilbao. I see that currently all teams in La Liga have already secured their positions for next season. Except for Celta Vigo who still have to fight for a UEL ticket with Rayo. And Leganes who still have a big chance to get out of the relegation zone.
In that case, Barcelona winning would make more sense. We have seen them win before, and we could see them do it again. We are not getting that much of a bad result, so we should be happy with what we got. If they can do what they normally do, then it's going to be fine and not a problem at all.
If Bilbao had anything to win, then I would say Barcelona already won, and Bilbao needs a win, then I would say Bilbao could of course win. But because neither team "needs" a win, then the better team would win and the better team is Barcelona at the moment. But a tie of 0-0 would be quite possible too. Because no team really needs a win, so they could just pass around and not really try that hard to get a win so they may not score.