Optimization Toolbox is not going to be removed in a future release. However, the Optimization app, which you can launch using the optimtool command, will be removed in a future release.
The Optimization app is based on Java, and that basis is becoming increasingly problematic. Additionally, the app has not kept pace with development; for example, you cannot optimize MILP problems or particle swarms ( intlinprog or particleswarm ) using the app.
In the time since we started announcing the future removal of the app (first announced in R2015b), we have not received any negative feedback, or at least I am not aware of any. I am sorry if the announcement confused you as to what will happen.
MATLAB mathematical toolbox documentation