No, I don’t think It’s possible that Chuck and Sarah will not get together in the end. The final beach scene is a reversal of the beach scene in the pilot. Chuck had been robbed by the spy world of five years of his life, was scared and confused but trusted Sarah and fell in love with her. Here Sarah has been robbed by the spy world of five years of her life, is scared and confused but trusts Chuck and falls in love with him. That’s the purpose of that scene. The whole final three-episode arc is a build-up to that final beach scene As the beach scene in the pilot was the beginning of a beautiful love story, this beach scene is the beginning of a beautiful love story. It’s a Goodbye that is a New Beginning.
And why wouldn’t Sarah fall in love with Chuck in this new beginning? By now, Chuck has all the qualities she’s always loved about him plus all the qualities she liked in Bryce, Cole, and Shaw. Even in the last two episodes, she keeps subconsciously gravitating towards Chuck, including her presence at that very beach. She can’t go back to her life before Chuck. He’s become a part of her core being, beyond memories.
What Schwedak leave to our imagination is not whether Chuck and Sarah will be together or not in the end but only whether Sarah regains her memories immediately with the kiss or not—which I think she does because her faith in loving Chuck (asking for the kiss) even without memories is rewarded with her memories.
Chuck and Sarah’s story was ultimately always based on faith, based on them always having faith in one another and in the hope of their relationship, even when it seemed impossible. And their faith was always rewarded. It will be here, too.