The population of Myanmar are the people living in the pre-war borders of Myanmar.
I will use my best judgement to determine how this resolves if the coalitions I specified merged in weird ways. For example, is a group of EAGs join the State Administration Council and their combined territories are governed together with meaningful but not total SAC control, I'll call that a successor junta. If these two groups ally but the SAC has no ability to enforce laws in the EAC territory then I'll consider that an EAC coalition.
Majority democratic/no democratic is determined by fraction of people within the coalition who can participate in elections about as free as the last pre-war election.
I'll determine that the war has ended if there is a treaty resolution to the war between >70% of combatants by estimated headcount, if there is an effective ceasefire between such a group for longer than a year, if one group is widely considered to have won the war in international press, or if the war is widely considered over in the international press. If e.g. a coalition of EAG destroys the SAC and declared victory, but within 1 month starts another civil war between it's constituents, that will be considered the same war.
This is a complicated one to resolve, feel free to ask for clarifications.