Photos from the post, for reference.

The side stones, chat box, and minimap in the original TLI don't obstruct the player's view at all because they are against the edges of the screen, while the character is centered in the middle. Moving all the stones to one side will make it feel like the field of view is smaller because the right side of the screen will be crowded with extra buttons that block some of the player's view of that side. This will require the user to zoom out more compared to the current TLI, or hide the buttons to free up some of the obstructed view.

It's possible the picture of the updated TLI shows some extra space on the edges to accommodate the xp tracker and a punchout camera. However, if that's not the case, the updated TLI will obstruct too much of the player's view, and the player will need to zoom out more than usual or frequently hide buttons to maintain a comfortable field of view, which will likely make playing on mobile feel less precise and more clunky.

TL;DR - Mobile already feels too small at times. Let's not make it feel smaller.