The Bulls don't necessarily have a rebuild offer which is why Flip may want that over what other teams have. Every other team would cause them to have to blow it up entirely, which they couldn't do even if they wanted to.
they can offer Boozer - an expiring
they can offer a bunch of future draft picks (esp the Kings picks)
and you throw Taj Gibson - it's a good start of blow up strategy, downside Is obviously Chicago will be in the playoffs - so outside of the Kings pick those draft picks won't be that high.