Regulated carriers have their own FAA teams assigned to them that they interface with regularly. GA is separate from that.
As long as someone makes the FAA aware of this, then they will look into it. They are required by congressional mandate to investigate any safety or regulatory matters...
I think it is because there are so many foreign students in training programs that rental pilots are more of a hassle than its worth. Plus the Corporate Jet market down here is HUGE and the regional airports have been driving GA out to make room for more Corporate activity.
I just completed my flight review after a five-year hiatus. I reviewed the FAA's guide to performing a Flight review and reviewed all the sections listed in the FAR/AIM, watched some YouTube videos, and listened to some LiveATC. No need to buy anything special, there is PLENTY of free material...