I don't dance was the climax of their flirting and Chad's way of coming to terms with not being straight (whether it be bisexual, gay or something else), so once the song was over they were set on each other, and became a couple unofficially. This pretty much builds to my conclusion of Ryan being a closeted gay character comfortable with his sexuality, who has an intimate relationship with Chad while he is struggling with his. Here's a link to the Quote (I know I know, it's buzzfeed, but it was an actual interview so I'll let it slide) Also, Disney is very careful about topics that might be taboo, and they still haven't really had a main character be gay in any of their films or tv shows (as far as I'm aware) because of a fear of damaging sales (in china for example), which is why they definitely wouldn't have an actual gay character on screen back in 2006-2008 as that time wasn't as accepting towards queer people as we are now a decade later.

Lucas Grabeel asked the director Kenny Ortega if Ryan was gay pretty much as soon as he had read the script, and even though he wasn't given a straight up yes, it was pretty much implied that Ryan was in fact gay. If I remember correctly, some (most) of the actors shipped Ryan and Chad, so Lucas (Ryan) and Cordon (Chad) did the outfit switch just for fun and it ended up in the film.

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