If you think this is a 'lengthy debate' you should probably look at the ones on the IL-2 forums. They went on for years. Hopefully someone can come up with some hard facts (i.e. a photograph showing the actual view through the windscreen) and avoid the same here.
As to whether it actually matters, anything that allows you just a couple more degrees downward visibility may sometimes be significant - it can make the difference between getting a deflection shot in, and not actually being able to see the target.
Anyway, the video was a brief alpha/beta shot, and as yet we don't even know if there is any real problem.