I think that's a dramatic take -- not aimed at you, just saying in general
The transfer portal plus NIL is without a doubt retaining talent longer and elevating talent sooner. So in the grand scheme yes talent will rise and lower programs will find it hard to be competitive. That being said, it's no different than supply and demand. G5 will take from other G5 quality and promote from FCS. FCS will steal within and promote from D2. D2 to D3. D3 is over saturated and honestly less concerning anyways. As a former D3 player, I don't think you will notice a ripple. The cream will still be at the top (Mount union, St. Johns, Bethel, etc) and the other 400 schools will fluctuate like usual.
That's the magic of Div 3, everyone is a Cinderella when you get to the tournament. St. John Fisher had a run, made it to the elite 8 and final 4 but then kind of falls off as the years go on.