Sporting Lisbon would easily get past the lose of Gyokeres it's not going to affect them much cause they're not a team that depends too much on a striker to win games moreover the huge fees recovered from the sale of Gyokeres is enough to get them two fast rising attackers then train them into becoming the new Gyokeres for the team.
Last season, Gyokeres played 33 games in the Portuguese league and scored 39 goals, while Sporting scored 88 goals. Benfica scored 84 goals. This means that if Sporting didn't have Gyokeres, the number of goals scored would be much lower than the 88 goals, and Benfica would be champions.
now see: Portuguese league winners
https://www.worldfootball.net/winner/por-primeira-liga/When Ruben Amorin left Sporting, the team didn't fall because the new coach didn't change anything in the squad, but now with Gyokeres' departure, he lost his best striker and signed another in his place:
Sporting CP have agreed deal to sign Luis Javier Suárez from Almería, here we go!
Deal confirmed as exclusively revealed in June.
€25m fee package plus 10% sell-on clause.
https://x.com/FabrizioRomano/status/1948476766454251796
With the arrival of this new player, the team left by Amorin is changed, the new coach will start to have difficulties in dealing with the team and Sporting will return to being that team of the past that did not win the title, as a Benfica fan that I am, I am rooting for this to happen and Benfica will win the title again in many of the next seasons

It's true that the departure of gyokeres will affect their goal scoring rate but I don't think that it will really affect them that much because I believe that they can use the money from the sell of gyokeres to buy two top strikers that can get them some good goals , it's only traditional for teams to struggle when a new coach take over because the players to adapt to the style of play of the new coach