The gas should always be able to flow to the EU through Greece no matter what, but Cyprus should not override the prospect of selling directly to Turkey as well, even for their domestic consumption because that is a lucrative deal.
Turkey must invest and cooperate with everyone to the maximus to get in on any Cypriot gas, otherwise her prospects of becoming a transit hub to the west get extinguished just like that. I dont fancy her chances much and that is not good for Cyprus either.