The loss, could be viewed in several ways.
For some it's the worst thing that could have happened to Miyazaki. He was supposed to move to Light Flyweight, win a world title at a second weight in 2014 then move up again to hunt a Flyweight title some where down the line. He's was unfortunately shown that Light Flyweight isn't really an option available to him and he also suffered a loss, not just a loss but an early stoppage loss to a man many had written off as merely a tune up opponent.
For others however it was the best thing that could possibly happen for Miyazaki. Right now he's learned the painful and agonising lesson of trying to cut too much weight. How he ever made 105lbs is a mystery and the fact he collapsed from dehydration after his recent weigh-in tells you everything you need to know. His loss, rather than being a bad thing, was the hint that he needs to fight at a weight that is natural to his body, not a weight that he has had to destroy himself to make.
For me personally the biggest danger in boxing is dehydration. All too often fighters dehydrate far more than they should in the hope of having a natural size or strength advantage over their opponent. I'm not a believer in this logic and would point fighters to the examples of Manny Pacquiao, Floyd Mayweather Jr, Timothy Bradley and Gennady Golovkin as fighters who fight at their natural weight rather than drain themselves to artificially low weights. The 4 men mentioned are all strong at their natural weight and are all better fighting in, or around, their natural weight then dropping a division and draining themselves.
If Miyazaki allows his body to fill out he's likely to be a Flyweight, incidentally where he started his career way back in 2006 when he was just a teenager, if not a Super Flyweight. Sure this would result in him giving away height and reach to opponents but with the fact he'll be 100% in the ring will help him much more than draining his body of liquids in the future and possibly seeing him suffer a major injury. There's enough danger in this sport already, so don't make it worse by draining down.
Incidentally Miyazaki, who as mentioned passed out at his weigh in, was unlikely to be able to make a name at Light Flyweight anyway. The division is where his stablemate Kazuto Ioka fights and although it was widely expected that Ioka would be skipping up to Flyweight in 2014 it appears that Ioka, the current WBA champion at 108lbs is very comfortable at the weight. If Ioka, as he did for his fight with Felix Alvarado, can weigh in with more than a lb to spare then there is no reason for Miyazaki to be trying to fight in the same division.
Next time out we'd like to see Miyazaki fighting at either Flyweight or an above the limit fight at or around 114lbs. He needs to put the loss behind and look to establish himself at a weight than he can feel comfortable. He's a very fun to watch fighter and someone I'm going to watch every time I can though if he continues to starve his body of liquid there is every chance his career is going to be over far too soon.
Before I finish this I would also like to ask, as an open question, what were Miyazaki's handlers thinking allowing him to fight in the condition he was in? They really do need to think twice before allowing something like this to happen again, as doe the JBC who should have cancelled the bout when they saw Miyazaki's condition at the weight in.