Currently, scrolling down below the player window in the YouTube app for Android will present the viewer with comments below the "Up Next" section of recommended videos.
Some users are now reporting that the YouTube app has hidden these comments by default, implementing a dedicated "Comments" button in the bar just below the player which also includes the like, dislike, and share buttons.
Pressing this button opens an overflow window which displays comments on the video, and users can close this window by tapping the exit icon which appears in the top-right of the redesigned comment section.
XDA Developers reported that this change has rolled out to some Android users in India, and could launch for YouTube viewers in other countries in the near future.