In my Axis with Boyds stock both types of magazines fit and function the same.
It may be that the old style is being phased out but I haven't seen anything "official" yet.
I ordered a couple "new style" replacement floor plates from ebay since I think I prefer the "new style".
I may end up not needing them, but if I order additional magazines online I won't know which is coming since they both have the same part number on the packaging.

Anyway - see here:
ebay.com/itm/253779135858


EDIT: No I am not the ebay seller or affiliated in anyway :)