Is anyone besides the fans saying ECW? If not then there wouldn't be much he could do. Even so, whatever. It's all promotion for his company anyway. TNA promotes ECW and then anyone looking for ECW merchandise or whatever pays Vince. Everybody likes easy money.
Technically Dreamer said it in his match against Abyss right before he did his Tree of Woe Drop Kick. He looked around, shrugged, and then said ECW with the crowd.
I doubt he could get into trouble for that simply by saying that's the name of his move "ECW drop kick" or whatever. Tenay and others have referred to them a time or two as the "ECW originals" but strictly as a fact, not as a name. I imagine that'd be the only way they could get into trouble would be to "officially" name them "ECW" or "ECW Originals".