4th Age Balrogs?

[Galin]

Originally Posted by Meoshi

Perhaps, but even so, the Silm tells of a "few" who escaped.

Just to add, this statement from the constructed Silmarillion is a remnant from the late 1930s when Tolkien imagined there were very many Balrogs (which conception continued into the Annals, written in the early 1950s).

If the idea noted in The Annals of Aman was going to be true, JRRT arguably had some more revising to do in Quenta Silmarillion, though we can't be sure he was going to give an exact number in any case. The lower numbers of the marginal note (possible written in 1958) wouldn't necessarily be incorporated into the tale, and were not in the actual alteration to AAm.