The DMG was a very late addition to the Roll20 canon. Originally it was waiting for certain Roll20 features to be added, whatever they might have been. Eventually it was added. This was loooong after the bundle was created. They would have to create a new bundle for it, and so many people already have the other items in the bundle or the old bundle, my suspicion is that it would not be worth the effort. As for what you get, you get the full text of the DMG (all the lore, advice, etc.), lots of new tokens and maps, the rest of the core magic items, not as many rollable tables as you might hope, the two classes you mention, plus the DMG versions of the eladrin and the aasimar. Whether that has value to you is subjective. My personal feeling is that the print DMG is the least useful of the three core books at any rate, at least for experienced players. My biggest draw would be the maps, tokens and magic items, plus a few rules for things like madness or the effects of planar travel.