sorry for length! i too worry about the d2/d3 impact, but i think the current setup of d3 is way unbalanced already, being so hard on rookies due to the RS2 nature of high end d3 recruiting, and with the massively talented high end d3 teams (way higher than ever before) slaughtering newer coaches - i don't think d3 should be much focus. plus the d1 pop is what is going way up, its clear from the post-jobs movement that d1 is where most folks want to be, so i think adjusting for d1 has to be the priority.
IMO they could also generate more d2 and d3 recruits, and probably would be easier for them to generate more for all divisions, based on the unified nature of the recruit gen process... plus plenty d1 recruits go to d2/d3. with d2/d3 so highly talented on a historical basis, and perhaps even more talent getting created, i think giving d1 teams more time helps restore balance. IMO the competitive balance demands d1 teams get a bigger lead over d2/d3 teams - and that complaint comes up fairly regularly - virtually nobody suggests d2/d3 should be stronger vs d1.
i think they have to be very careful if they start messing with recruit generation, though - it is not an easy thing to tinker with, and one of the better improvements of 3.0 was lowering the talent level of top tier d1 teams, to allow more variation in teams and a wider band of competition, basically overall fixing the competitive balance at the top, which was out of whack. IMO, making higher d1 more competitive was the greatest achievement of 3.0 and one of the greatest balance adjustments in HD history. plus d2/d3 recruit gen changes have balance considerations, too.
last thing i'll say - adding medium caliber d1 talent is the way to go IMO - there are enough great and elite players already. so if adding, add some serviceable guys and a few good-but-not-great players to fill out the ranks, make it easier to fill out teams, get backup options. ideally, base the numbers on human pop (or human openings), to reflect the reality that more humans makes it more competitive. (today recruit gen is partly based on regional d1 openings, including sim openings - regional human openings would be ideal). or don't add players at all. or maybe just shift some to LATE. but i don't think adding a bunch of studs is a good idea.