He’s come out fighting for his place, at least, and shown that he’s a pro - not seen a whole lot from Emery’s other “5 captains” so far (although I’ll be generous and let Koscielny off).
I don’t think Emery has any problems with Leno - after reading his comments, it seems to be simple case of Cech having done nothing to lose his place yet. He’s last year’s no.1, had a good preseason and has played well so far. Plus the current porous nature of our defence might be making him think it’s not the best time to chuck a new keeper into a new league?
2/3 years ago, Leno would have been mentioned as one of the top keepers in football. He came off a bad season in Germany, that may have damaged his confidence and his stock dropped a bit. He's moved to a new club and may just need a few months or so to recalibrate and get his confidence back.
Seeing how crazy the keeper market just went and the fact that we have an ageing keeper on our hands, maybe Leno isn't meant for right now but for when we eventually need to replace Cech. Similar to what Juve did to replace Buffon?