When fans first began to suspect that Ellie was gay after playing through Left Behind, there was some uproar around the news. Some fans felt they had been misled because Ellie didn't appear to be gay in the first game, while others tried to find ways to explain away Ellie's kiss with Riley in a way that made her sexuality slightly more ambiguous.
That became impossible when The Last of Us: Part II was released, but some fans nevertheless wished it wasn't the case. Thankfully, that controversy has largely come and gone, and the reaction to learning that Ellie is gay on the show has been much more positive, on the whole.
What matters just as much as Ellie's sexuality, though, is learning how she lost the person she was closest to in the whole world. Joel may not think that Ellie has any conception of what loss really is. As this episode illustrated, though, she very much does, which is one of the reasons she remains so afraid of losing Joel.