Even when the "Rename Test Class" option is tick marked, only the source class name is changed, the corresponding test class' name does not get changed.
I guess the milestone should not be 'Next' ;) since it's used for bugs which are planned NOT to be fixed in the current dev version (and the corresponding future release) . Also please do not change the target milestone at all unless you're planning to address the defect in that release/timeframe yourself; it's a planning tool for active contributors.
Should be fixed in jet-main#eb81e2478e8b
Integrated into 'main-silver', will be available in build *201703160002* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
User: Svata Dedic <email@example.com>
Log: #268540: fixed deadlock between EDT and asynchronous query. Junit calls callback immediately, not in EDT