Arsenal have literally benched a number of their players today, likely for the game Champions league game against Real Madrid that is coming up during the midweek. Odegaard, Saka, Maritinelli and Timber are all on the bench for this game, I hope they'll be able to get a positive result here and it won't come back to hunt them.
Although mathematically, Arsenal could still win the Premier League, but that would depend on Liverpool's performance. As a result, I believe that the league's hopes are all but gone because Liverpool is not prepared to lose, and their elimination from the Champions League means that they will put in a lot of effort to win the league. This is football, and anything can happen, but I do not see any hope for Arsenal.
Some key players were rested, as you mentioned, but Arsenal still has the players to give Everton a tough game. The focus is on the Madrid game, and Arteta is preparing his players for the big game. Arsenal will undoubtedly hope to advance in the Champions League to avoid going trophyless again this season.