Trooperman said:

^^ I am convinced that the scene with Obi-Wan was intentionally blown out that way.

If you notice, the part before Obi-Wan comes, which is in the same location, has normal colors.

It's precisely when Obi-Wan appears that the frame turns white.

For home video, they were probably trying to correct everything to "normal" and so they saw these blown out whites as a mistake and regraded it to match the part that had come before.

That may indeed be the case. It does look blown out but as you said it may very well be how they intended it to look.