Zap2it is saying that BAG's casting in the CW show will be second priority to T:SCC. If T:SCC gets a third season. He is not leaving T:SCC, if it's picked up again.
This may need quoting. There is no evidence BAG is leaving TSCC; the actor would outright be lying if his character is dead by "Born to run", the closing episode of S2 of TSCC (which BAG absolutely does not need to leave, he is getting more kudos as an actor than ever before, his character is great). Not that this is impossible, as Leven Rambin also was a bit misleading in what she said before Riley's death was shown, but it would go a bit far to claim "TSCC is my first priority if it gets a third season" if he knows his character is gone.
TSCC viewing numbers are on the rise again and its recent 2-parter got quite some critical acclaim (and is liked a lot by the fans), so it's not over yet. FOX is expected to decide by may, and WB still wants to keep TSCC on the air.