I disagree, the goal of BoP is that any car can win any race, its purpose is to create close racing, and not have the situation where on car dominates no matter what the track. In GT sport a lot of data is now being generated so better balance can be achieved and PD have made a decision to adjust it based on that data.
As you used the WEC, This year BoP in WEC is adjusted on a race per race basis by an automatic algorithm (the adjustments started following the data acquisition in the first two rounds). This is to try and maintain as balanced a field as possible in GTE, so any manufacture has the possibility of winning a race. Le Mans has a race specific BoP as the track is so different to anything else on the calendar this is predetermined at the start of the season.
Ford GTE didn't compete on a waiver from the FIA/ACO, the other manufactures agreed that it could race the GT in GTE form, the car was built to the same rules, the only problem being the road car was not available for homologation. Ford also sandbagged prior to Le Mans, they even got hit with a BoP adjustment after qualifying that year to try and slow them down... So it is constantly evolving thing in that Championship.
GT3 on the other hand is more rigid, it is set at the start of the season, which is why you see that some cars favour different types of tracks

This is also why BoP is a big talking point in Blancpain for example...