Yes. It is self-reported. It's just another source. I don't know of any other that would address the question at hand as directly as this one.
The bottom line is that a lot of programs, most likely, do not want to share what their parameters are. No program will openly say - "We get about 1500 applications. We first filter by Step 2, need to be more than 240, then we look at the number of honored clerkships, and then we read letters looking for phrases like 'excellent' or 'wish they would stay at our program.' Then we interview and look for XYZ, rank, and then we usually fill in the range of 80th-120th spot on our rank list." This would make the program look undesirable (Why do the first 79 people want to go somewhere else?).
As far as TexasStar is concerned - I have no idea how it is affected by reporting bias. Is it like with the Step 2 CK scores this year where there was a period of time that people thought that the new average was 260 because of so many people reporting their score in the 260+ range, despite it being written on the score report - the average is 248? Are well-achieving candidates more likely to report their match results? IDK
We are the first class with a P/F Step 1. We are the first class with new signals (like anesthesia - 5 signals last year - 15 signals this year, 5 gold, 10 silver). We are a class that is still being experimented on in terms of geographical preferences. We are a class that is being experimented on by using a different application platform (Central App) for some specialties (Neurology, Urology, Plastic Surgery...)
What is not helping is the fact that there are programs out there that decided to start doing stuff like that (Central App) TODAY, two days before applications are due.
What I wish for is a centralized system from the NRMP that would allow us to plug in our metrics and give us a percentage probability of matching to a program. It's probably far from being possible.
What is possible and totally doable is for letter writers to not string us along till the very last minute and just submit their letters way ahead of time. Still waiting for 3 (!) letters...