You are right the Sevilla team has not focused specifically on LaLiga for the Europa League. But in my personal opinion, Sevilla need to do great in La Liga too, because there are enough opportunities in this league. With nothing more likely to be done in La Liga this time around, it's only fitting that Sevilla do something great in the Europa League.
Maybe it's because Sevilla are very aware that they are still unable to compete hard in La Liga so they put more focus on the Europa League which won't be bad for Sevilla either. Because Sevilla certainly knows how their rivals are in La Liga, so Sevilla really has to have better strengths if they want to focus on La Liga starting next season by beating teams like Barcelona and Real Madrid and several other teams as well.