I indeed learned recently about those 2 hotels in LP being taken over by Accor. I've been before at the 3 Nagas and it's a nice boutique hotel with an excellent restaurant. It is already bookable. IIRC, they had different kind of rooms, so upgrades are possible in theory. But it's a small hotel anyway.

For the hotel de la paix, it was not bookable when I tried a dummy booking 2 weeks ago. It seems that there are only suites in this hotel.

Very good that Accor is having (nice) locations in Luang Prabang ^