I imagine it’ll be burning. There’s no way they can sift through it all. It’ll have to start happening by the weekend or there will be the danger of disease.
I think you're right.
The path of devastation is simply to huge, and the time and manpower too short, to attempt to sift through all of it for bodies. I'm sure there are gov't health officials who are tasked with making a decision on this within the next day or so.
The burning, itself, will likely cause even more emotional loss for the Japanese people (on top of everything they've already endured).
I wish there was a better solution for them, but I don't think there is.