You are right, my bad. Sorry
I thought the US that have floodable welldecks were only LHA, but some American LHD have as well
Actually you are still a bit incorrect there.
There are many LHD classes in the world outside of the US as well.
Spanish/Australian/Turkish - Juan Carlos/Canberra/Anadalou class
South Korean - Dokdo class
French - Mistral class
Italy - Trieste class
Those ships (LHDs/LPHs/LHAs) all have floodable well decks as well.
Floodable well decks are not an exceptional or unique feature for LHDs or similar ship types, if anything they are very standard.