Square will stick with FFXIV for a long time. Remember they had FFXI for many years. It will take many years for a newer online FF. The market will change till then and things will be really different by then. It is more profitable to stick with 1 good MMORPG than throwing money on a new which may fail. FF14 2.0 was a success and now they need to maintain that success. So no do not expect a new online FF for the next couple of years.