Could my "ex" who is going through bankruptcy proceedings be freed of a child support debt owed to me if he is granted a "release" from his debts and declared bankrupt?

This is extremely unlikely as child support debts are protected in bankruptcy proceedings, and only in the most exceptional circumstances will someone who is declared bankrupt be exempt from a child support debt. For example, as an exception, in extreme circumstances, in September 2013,Tel Aviv District Court granted a debtor,a 75 year old professor in poor health, a complete exemption from all his debts, including a long-standing maintenance debt, concerning a child now in her 40's, but stressed in the ruling that this was an outstandingly rare case, and that in general the exemption given  in bankruptcy proceedings does not cover maintenance debts, and that any claims regarding inability of the debtor to pay back those debts, because of poor health and financial reasons,must be dealt with at the bailiff's office, and not in the bankruptcy court.

The case and a similar one given by Haifa District Court in 2014 were mentioned during a hearing at the Bailiff's in November 2017 where our offices represented a debtor in proceedings regarding an alleged child maintenance debt from the 90's.