Disagree. I know Montague lost to McCall a little over a year ago but he is still a young fighter that is improving. He looked great in his 2 fights since then and no doubt about it he is a top 10 and working his way toward the top 5 right now. There are some guys over in TPF and Japan still. Even some of the 115lbs guys can come in and add depth.
The UFC isn't ready to expand the division as deep as the others. It is still extremely new to the UFC.
Bottom line is they have all the top 5 flyweights in the world. 115s aren't going to come in and do anything when 135ers are dropping. Japan fighters really aren't good anymore, they rack up wins over on that circuit, get built up...then flop in the UFC. I can't think of 1 Japanese circuit fighter who has translated well to the UFC recently.
Like I said, sure they can go out and accumulate MORE fighters, but they have the best right now. They have went out and signed the divisions #1 fly a few times already. But they already had the best flys in teh world...they were just in the 135 division.
It will grow slowly just like 135 and 145. It isn't plausible that they just go out and sign the best 20 flys in the world all at once. Many of those guys don't want to come to the UFC. Many Japanese fighters want to stay on that circuit and be an elite fighter there than an average UFC talent. When fighters separate themselves from other the UFC will snatch them up when they can.