>Let's have another summer next year, okay?
Lmao, if anything it just reinforces that this will be the last Summer event, at least of the ones starring Guda.
Even if you take out the countless hammering-ins from the story and a bond CE that insist that we are about to head into the ultimate conclusion of Chaldea and Ritsuka Fujimaru's 10-year-long story, there are plenty of things that pretty much hammer it in as well even if it's not invented to be.
Dialogue promising the other that they will make it for another time is a huge death flag.
One of the Guda's dreams is to open up a bakery with the ones he love. Usually, something like that being stated explicitly is also a death flag.
Not to mention, Guda started out as a somewhat selfish man with his own concerns who only fights because he has no other choice since he didn't intend for things to go the way it did, with the bombing in Chaldea and being the only Master left to do the job, to a man worn out by years of fighting, who saw and witnessed a lot of traumatic shit firsthand and grew to be more selfless, eventually culminating in what may likely be a reset ending with an ultimate sacrifice to give up his chances to go home in order to save humanity.
We had Olga's Bond CE, that apparently takes place post-story, indicating that a heroic sacrifice may have occurred and Guda became forgotten, and those who didn't forget would just move on and keep on living, just like Guda wanted for himself at first.