The LaserDiscs do fade to black and back again at the side changes.

For ANH however its a straight cut so it wont be noticed, for ROTJ the side changes occur where there would normally be fade transitions so the fade to black and back again doesn't stick out too much and is very brief. The side changes on ROTJ occur in two places first between the Rebel shuttle approaching Endor and the Shuttle Landing on Endor. Second between the Rebels first entering the bunker and Luke arriving on the Death Star with Vader.

The one that will stick out the most will be ESB. With ESB the side change occurs where there would normally be a diagonal wipe between the Falcon escaping from the space slug and Luke training on Degobah. The problem is the diagonal wipe is still in place however now it wipes to black and then back again.

I have already played with getting the ESB transition to look right, the results were less then successful, I will probably take another look when I get to ESB next week but I'm not optimistic.