Np.

It's triggered on level-up(because it is level-up, but there may be times when a GM has to ask them to hold back on leveling for narrative's sake, I guess), and, as of now, the requirements are DM's Choice. In this setting, no, you won't revert and achieve an alternate form, not unless you get knocked back significantly far- then it can happen, if there's a significant difference in care or the dynamic between the two. I hope that answers your question.

Well, just in case something happens where it wouldn't be necessarily War Greymon, or, if something awesome happens and I think you could get something [i]better[/i] than WarGreymon.