I'd think we are getting close to a steady state pretty soon and this slows down. It's not like there is a growing number of G-league and NBA roster spots. It's easy to say, "That guy is probably not NBA material, but he'll just go to the G-league." No matter what, all of the guys entering the draft and FA have to take a roster spot from somebody currently in the NBA or G-league. After a few years of marginal guys heading to the G-league, the college talent is getting watered down enough where there just aren't as many guys good enough to take roster spots. Now if you start seeing a higher percentage of guys make the NBA after playing professionally overseas, that's where the further dilution is more likely in my opinion.
The next step with the G-league will be drafting kids right out of high school. This will have a huge trickle down effect on the non blue bloods but the 4 year player will be much more common again.