No, he wasn't, but that happens when:
A) Illinois' depth chart is better than the teams on his list
B) Priorities change, needs of position change when you see your guys and they're better than expected and going to be stars, and lastly, recruits' position on the board changes when other recruits (Corey Lemonier, Shariff Floyd, Dior Mathis, CJ O the DE from Michigan, etc. etc. etc. start to express interest). Plus you have one guy who's going to be on board (Calvin Smith) so...they're still going to recruit Gaston but stuff changes, and Smith was higher than Gaston on the board from the start (Gaston wasn't even on the board until spring). I personally really like Gaston and think he has the potential to be a BIG time DT. And just FWIW, I don't think that is his final 6.
C) Finally you have douchebags like Tom Lemming and Taylor Bell going all out against Illinois. CJ F was their little baby and when he committed to Illinois, that set off a firestorm. I just can't wait until the season starts to shut these two up.