First of all, you're comparing two different kinds of advanced statistics. Win Probability is a well understood concept and is frankly, inarguable. The idea that they indicated we had a low probability of success is inaccurate is a puzzling statement. The reason the F-Bomb was such an impressive play is because not only was it a physical feat, but it was a MASSIVE turning point in a game which we were clearly about to lose.
Sabremetrics are less well understood in terms of application to football, but they are totally unrelated to WPA, so I'm confused as to why you brought WPA up. It's like we were all talking about our favorite MeatLoaf album and you posted about how terrible meatloaf tastes. The two ideas merely sound the same, they're completely unrelated.
Ok it may have came out wrong. My point is that sabermetrics are not the end all be all when it comes to evaluating players. It may be a big part, but it's not 100%.