[Thingol]

"But what if we assume that the '3 or 7' note is from the same time as the correction to the Battle of the Powers passage in Morgoth's Ring (and all indications are that these were simultaneous changes)? Although he changed 'a host of Balrogs' to 'the Balrogs', he retained their being slain by Manwe. This is problematic. If he seriously considered reducing the number to 3, how can he have retained the idea that any were slain? Certainly re-embodiment can be ruled out in this case; the death of Gothmog is treated always as if it were quite final, and none of the characters suggest that Durin's bane might have been a re-embodiment. Perhaps he meant to make them not be killed by Manwe? In this case, though, he surely would have made the relevant correction to the text. Quite puzzling."
Aiwendil, The Seven Thains of Morgoth

Later in that post, obloquy you suggested that the mere notion that Tolkien was considering the number 3 suggests that he was planning drastic changes. I agree with you there, the only difference is in the degree of change. If he had actually desired to change the number to 3 or 7 why did he not do so?

"It is a mistake to assume that the note is inconsequential and that the author probably didn't mean anything by it."
obloquy, this post

I agree to disregard the note is a mistake, in fact I agree with you obloquy, that we must take the spirit of the note to reduce the Balrogs in number; but it is equally dangerous to read too much into the note, after all there is no other mention of the number 7 anywhere in Tolkien's writings.
P.S. sorry the quotes aren't in that little box thing, but the quote button isn't working for me.
P.P.S. lol no wings, don't get me started Mr. Underhill