this is the character specific stuff that is going to really make some characters
I don't think this helps Link and Toon Link that much as you can only throw the bomb forward, you can only cancel the lag specifically on landing like a tech (if you land and don't press down-B instantly or if you try to do it on the ground it doesn't work at all), you can't Z-Air and recatch the bomb in the air, and there aren't that many "laggy" moves you can realistically cancel.
With both Toon Link and Link you could theoretically cancel: Up-Air, Down-Air, Boomerang and Arrow. (Z-Air, Forward Air, Neutral Air and Back Air all auto cancel on landing anyways). That's a total of 4 moves, and out of those 4, 2 of them require you to throw the bomb upwards and then recatch it. I don't see this being used THAT much.
With Peach I have no idea, I don't really know her that well.