What happens when Prince Leopold, son an heir of Leopold II, dies a couple of years later and Philippe becomes heir apparent to the Belgian throne?
... yes of course, butterflies, I know... little Leo could also just not fall into that pond and not die because his uncle went off to Romania.
But assuming he does there would probably be a lot of pressure on Philippe to abdicate and return to Belgium since he has no sons yet him self. So that doesn't bode well for Romania going through two Kings, two dynasties really, in quick succession.