Worked on ships all my life and now in shipping, its not as easy as just sending an ROV down. I think their main concern will be not to lose the bodies. Heaven forbid they somehow get inside and the body or bodies go drifting away with the tide. 2 or 3 knots of tide and they'll be away in no time.
I read they're also thinking about recovering the plane itself. If the plane breaks up during recovery again the body or bodies could be lost.
I would imagine they'll send divers down, I think I read its 60 mtrs deep, there will be risk assessments to ensure the divers are safe to go inside the plane if need be.
As it happens I've just done a risk assessment here where I am for shallow water, its taken 3 days all told to get approval from the powers that be.