Yes, it would have taken time if he had a crush on a girl and explaining that.
However, what if Searcher and his wife had a daughter? The trend nowadays for female characters is that they do not need a beau to feel complete. I'm convinced that if Ethan had been a girl, she would have stayed single.
That Ethan is gay is not something that adds to the story, or him being in a relationship/flirt adds to the story. There is not enough danger that Ethan needs someone worth fighting for or to return home to. If you take out the gay angle, nothing in the story changes.
I think they made Ethan gay for 2 reasons, 1. to tick a box on the inclusivity list, and 2. to work up to have a gay lead one day. Disney and/or the US audience is not ready for this yet (or Disney thinks they are not ready yet).
With some more thinking, I do not mind that they tick boxes. I get suspicious when they want to tick all the boxes at once. Disney doesn't release that many animated movies a year. Maybe with ticking all the boxes at once, they feel like they have a clean slate they can work from in the future?