Forget any restoration. The best the former royal family can get is a semi-formal position and that is what they have now. This means that they are acknowledged as part of the great patrimonium of Romania and that the State (and society) respects them as such but that there is no restoration.
Like in Germany, in France, etc. where former royals and nobles have a position in society. On all those numerous historic estates all over the country, they try to continue and to preserve their wonderful patrimonium and continue to uphold their standards. Often they (like the Duke of Bragança, the Crown Prince of Serbia, Princess Margarita of Romania) are invited as special guests, as guests-of-honour, given a prominent place. being treated with all égards and respect. This works also on local scale: the local noble from the castle outside the village will also be a prominent guest on the annual fair, or sit in a committee, or a council, or in a board, etc. So their position has evolved from a political to a social position.
Romania (or Portugal, or Greece, or Serbia) back to a monarchy: forget it.