Just last night I reread part of the late Arthur Laurents' book Mainly On Directing: particularly the section on West Side Story.
What stands out is that he basically confirmed Tony x Riff as canon.
He wrote that "Probably, at that age, there was some homoerotic element" to their friendship. He described their first scene together as "a love scene" and described Tony's departure from the Jets as "the end of a love affair." He described Riff as a "vulnerable lover" toward Tony, and wrote that even though Tony moves on from their "adolescent" relationship, his love for Riff is what first shows the audience that he's capable of the kind of love he ultimately shares with Maria.
Mike Faist's recent interview comment that Riff and Tony's love story is his favorite aspect of West Side Story is more than just a joke. (Although Arthur Laurents would never have said that Maria was "in the way.") If you want a canonically gay Riff and bi Tony, you have support from the very man who wrote the stage script!
