There should be no reason that any exchange would not support a soft fork upgrade.. all the exchanges need to do is update their wallets and they shouldn't have any problems. and stuff like that is something that is usually done after a new wallet is out and working. If there was any thing such as a name change or something like that then some exchanges get a bit cranky and want to charge a new listing fee just like starting from scratch.... but wallet upgrades and bug fixes are a pretty normal thing with most coins. and really no reason an exchange would not support a wallet upgrade or anything that makes a coin more secure.
If the current remaining team members still has an access to PRIVCY GitHub then 100% sure Crex24 and other exchange will accept the soft fork wallet update, If there's none and using a new github account for the source code of the soft fork wallet is already considered as a new coin by any exchange and most of the time they will not support such actions.