I really dislike auto-play so I have always strategically rested my cursor in between the columns of video. Now, as I scroll, my cursor will end up within a column that is misaligned and start autoplay. The worst!
It's kind of silly that they add these attributes to each nth item based on what they expect the grid width to be, when you can get the same layout without them (my YouTube extension mentioned elsewhere in this thread performs this style fix so grid items line up properly when videos and entire cross-cutting shelves are hidden and the rest flow to fill in the gaps), but I suppose they have no incentive to make the layout work when videos are being hidden or the grid is otherwise being modified externally to work in a way they didn't want.