The main rumor going around the 'Net lately is that Chord was originally added to the cast as Chris Colfer's (Kurt) love interest on screen. As time went on, they saw how well he interacted with Dianna Agron (Quinn, who I am falling more and more in love with as the season goes on... remember, I'm still new to the show) and they changed his role... which basically means he wasn't comfortable with the whole gay angle.
Another actor, Darren Criss; will be playing "Blaine", an openly gay student from one of McKinley's rival schools that will eventually interact with Kurt as a "mentor" and turning into something more.
Of course, back in the day; Chord (who I genuinely like and of course, he's just beautiful) would've been fired had he not been able to do the task at hand... but people are falling in love with the character of Sam and... well, there you go.
It's weird, though. They've been pushing that Kurt and his "new love" will become a power couple of the school and of course, with Sam being on the football team, that would've automatically elevated him to that status... it's just confusing and it kind of sucks.