Word on the street is that Ivan Johnson will be drawing interest from the NBA after a solid season of basketball in China. Atlanta appears to be a front-runner in signing Ivan. This is not only because Atlanta offers Ivan familiarity with the city and yoga studios, but also for contract considerations.
The Hawks can offer him more than the minimum salary, up to the Room Mid-Level Exception in fact. But more importantly, if Ivan signs with the Hawks then at the end of the season he will be a "Qualifying Veteran Free Agent" (commonly known as Bird rights). The Hawks may have renounced Ivan to rid themselves of his caphold, but this does not preclude Ivan from earning Bird rights:
"Qualifying Veteran Free Agent" means a Veteran Free Agent who, prior to becoming a Veteran Free Agent, played under one or more Player Contracts covering some or all of each of the three (3) preceding Seasons, and who either played exclusively with his Prior Team during such three Seasons, or, if he played for more than one Team during such period, changed Teams only (i) by means of trade, or (ii) by signing with his Prior Team during the first of the three (3) Seasons.Article I, Section 1.(tt) (pdf page 18).
The Zhejiang Golden Bulls are a professional basketball team, but they do not participate in the NBA and therefore are not counted as a previous team. So long as Ivan signs with the Hawks (and only the Hawks), he will have Bird rights this upcoming offseason. This could potentially benefit both the Hawks and Ivan in a sign and trade scenario, or even in a scenario of the Hawks resigning Ivan. This is not to say both parties will benefit, but if Ivan plays like he did in China then the likelihood of Bird rights being used increases.
No matter what option Ivan chooses to go with, one problem he could face is Restricted Free Agency. If he performs well enough to warrant future consideration in the NBA, whichever team he signs with can extend him a Qualifying Offer thus making him a Restricted Free Agent. This is because Ivan went undrafted and will have 3 or fewer years of service in the league.
So Ivan, you might as well become a Restricted Free Agent with Bird rights and play in Atlanta again.