We are all well versed with the feature on Youtube web where the currently playing video is followed by a contextually relevant video, which ensures a continuous playback for you. For most parts this can be a minor irritation as if you leave the tab unattended in the background, it automatically starts playing video which would make little sense to you at the time, but if you are plugged in and working a long night, there is a plenty of discovery that you can do this way, where you are not too concerned with what is playing.
Either way, ‘Up Next’ is your typical coin, with you very distinct two sides. Whichever side you are on will decide your reaction to the news that the feature is coming to Youtube mobile application. Android Police has published screengrabs of the feature showing up on mobile. Just like on the desktop, the mobile app will also give you a list of upcoming videos, and not just the immediate next video.
With internet connectivity over cellular data still a major issue, unless you are on a Wi-Fi connection or in an area with solid 4G and a 4G enabled smartphone, this continuous playback of Youtube especially on mobile is not only going to be a drainer on your data but also on your battery life. The move seems to be a server-side enabling, so you would be advised to keep an eye on the same.