I think Cartoon Network and Toei would take a little bit more time to let the new dub gain footing before taking it completely off the air. Also, Toei did just give FUNi the rights to the toys, which means that Toei is not having a falling out with FUNimation, or those rights would never have been acquired. I can say with full confidence that FUNimation still has the rights to One Piece, and that at the end of March, it's going to take a short break (maybe a month or two) and return to the air afterwards.
When FUNi announces they aren't producing any more episodes (or someone calls to ask about the schedule drop and the person on the other line says they aren't producing any more), then I'll be worried. When 4kids announced they weren't producing any more episodes I called it that Toei took away their license to the show, and that FUNimation would pick it up.