I think the C's say no.
At the end of the day, Celtics end up with Sanders instead of Rondo unless they are willing to give a big extension to Knight. Clearing Wallace is nice, but now they're committed to Sanders into 2018 which is iffy.
For the Bucks, it might work out as they would have zero contracts on the books for 2016/2017. So theoretically they could resign Rondo for 2015/2016, then Henson for 2016/2017, then Giannis for 2017/2018 and have free reign on the rest of the roster. Imagine if they managed to sign a FA Drummond in 2017/2018... Rondo, Giannis, Henson, Drummond =).