I think they will wait and see what happens with FF14 first, if it flops again then they will probably push a lot of money and effort back into FF11 as their only successfull and profitable mmo. FF11 still has the potential to bring back all the older players and attract new ones, it just needs more investment and more staff again as it used to have.

If FF14 does well enough they will just let FF11 stagnate more.