I always thought the late Queen and Charles thought Harry would end up like Sarah Ferguson - she went to the US and gave interviews slagging off the family, she wrote a nasty book and then did a number of projects like Weight Watchers and flogging stuff on QVC while running up massive debts. She came back and was allowed to live in Andrews home (not given her own!) and her debts covered by him (so by the Queen) on the understanding she was quiet and as invisible as possible.
What they hadn’t planned for was Harry being so much more famous and popular than Sarah, the money isn’t running out as quickly as it should and he doesn’t seem to be holding anything back to be able to rejoin the family. The sales of Spare have caused a massive problem - the level of interest means H&M can command large sums for their projects because they’ve proven unusual international interest.
Chances of him running out of cash and having to come home and do as he is told are now looking slim. and I’m pretty sure that there is no plan B for dealing with him.