I'm more of the opinion that there was a Q2/Q3 deadline to get some sane regulatory framework by the Libra team and they just whiffed on it or it was wholly insufficient for normal international banking standards (which was probably laid out by all the parties that left). The fact that everyone seemed to bail all at once sounds like there was just a lack of commitment/slipped deadline by the Libra side. Generally as a new thing is being stood up under a regulated framework there is some slack provided to get the ship in order while other interested parties look on, but at a certain point major requirements must be done. If you are one of the interested parties and it doesn't look like the other side is making sane progress, the hammer drops swiftly.