I'm guessing this procurement is off the shelf. Hence the requirement can reasonably be expected to have been informed by capabilities which are available now (automatic loading), or could reasonably be expected to be developed in a few short years.
On small arms i keep seeing different stories on line. Is the US going for 6.5 mms or 6.8 mm for its new rifle calibre? I'm guessing that whatever it chooses will be followed by us, the Canadians, the Aussies and other NATO.
What'll be interesting is with increased Russian aggression is whether the Modernizing Defense Program puts increased emphasis on not just the quality but also the quantity of heavy armor. If the latter where would the manpower come from, the light cavalry units?