It is true, The Europa League offers an easier path to securing a Champions League spot, especially for teams from Europe top five leagues. Aston Villa is a perfect example, they failed to get a Champions League ticket despite collecting the same number of points (66) as Newcastle in the Premier League. So it makes sense that they would use the Europa League as an easier path to the Champions League next season.
I don't think Europa league will be an easier way to get UCL spot for the next season. Only the winner will join UCL, it won't be easy to be the UCL winner. Even if the UEL teams aren't as strong as UCL teams, but winning UEL should be a hard thing. Anyway, there is no guarantee that Aston Villa will be the champion and secure the UCL ticket for the next season. Aston Villa may have the strongest squad in UEL this season, but the underdog teams can defeat them. We also don't forget that Beşiktaş, Roma, or Stuttgart are also strong teams as well.
In my opinion, Aston Villa will indeed be one of the strong candidates to win the Europa League next season, and Nottingham Forest might also be on the list of favorites. AS Roma and Real Betis are also worth favoring in my view, but it's still too early to assess the chances of each team right now. The Europa League is sometimes full of surprises, and some teams make it a top priority to achieve their goals.
I can agree that Aston Villa is clearly one of the candidates of the champion. Nottingham Forest could surprise us last season, but I doubt they can give a surprise in UEL. I prefer Roma and Betis to be other candidates. I admit these teams quite strong, they won't be easy to defeat by EPL teams (including Aston Villa). However, UEL often surprises us, any team can be the champion although they aren't favorite teams.