It looks as if a couple of postings have been lost from here (because of an unannounced server shift by our hosting company) so I'll try to recap what I said in mine, at least:
I wouldn't set too much store by what the UN agrees to. Usually they'll go along with whatever a government says it wants the country it governs to be known as. (The only exception I can think of offhand is Macedonia, which agreed to be called the Former Yugoslav Republic of Macedonia because Greece threatened to block EU aid otherwise.)
I fully accept the point about England vs UK, being something of a mongrel myself (none of my grandparents were fully English). But as I understand it, in the original language "Myanma" means exactly the same as "Bama" - it's just that "Myanma" is the literary word whereas "Bama" is the colloquial one. So "Myanma" is no more inclusive of the minorities than "Bama".
So to use a similar analogy:
"Bama" = "England"
"Myanma" = "Anglia" or "Albion"
(Sorry, "Albion" maybe isn't an exact parallel because poets have also used it to refer to the island of Great Britain, or on occasion Scotland. But you get my drift.)
I'm open to persuasion (and confess that my main source for the language point above is
Wikipedia). But for me the fact that the NLD are still using "Burma" is pretty persuasive.