Tron had a business agreement with the 2 exchanges (+Poloniex, a separate case), to help them get the consensus, implement their soft fork and release Steemit, Inc. funds, while immediately after pushing for a hard fork to shorten the power down period 3 days so that exchanges can have their funds back right away.
A very bad business deal on exchanges behalf. They must have known there are a bunch of IF's here, big IF's, or they are stupid, which I don't think they are.
As about using custodial funds ... let's say you're a broker and you're using clients money for yourself, let's see what happens to you.
I don't even want to get into that. I'm as pissed as everyone for that. Even more because from their post factum communications looks like they're doing it frequently without second thought or anyone questioning it... until now?