Titans need not worry.
While fifteen years may not seem like a long time in science, in politics it's enough time for another administration to redirect the funding. Just as the whole 'return to the Moon' fiasco is the Republican party's means of funneling government contracts and money to their big campaign contributors, the aerospace companies, that could all change if they fall out of control. If the Democrats take over, that money may end up going toward building roads or other infrastructure. So, it's best to say 'maybe' NASA will send a drone to Titan.
Have they accomplished anything toward building this drone besides an idea on a piece of scrap paper? Where are they even getting a plutonium core as it's a product of atomic bomb manufacturing which hasn't been done in decades? I thought the stuff was pretty scarce,