Who knows what "groove guard" is?

I suspect (but not positive) that this refers to the raised lip on the outermost edge of most LP.

In the early days when LP's were dropped on top of one another by record changer turntables, the lip provided a much needed space that prevented the grooves from touching. This was necessary to allow the freshly added LP on top of the stack protection while gaining momentum from a dead stop when dropped.

If they have done away with this, the LP will sit more perfectly flat on most turntables, although some such as the Walker have the platter turned just enough undersize to remove this problem on all existing LP's.

I am not even certain that I am right. The concept of removing what is no longer needed to improve modern reproduction is just a guess on my part, knowing the dedication of the folks at Classic Records.