My personal goal is to release it somewhen this year. Other than that, all I can give you is "as soon as possible".
We're a limited number of people working in their free time on the project, I wouldn't want to put others or myself under pressure, by setting a fix date.
The Scancode feature is closer than ever to the finish line and other points have mostly been addressed.
Next hurdles will be to do some final verification of the Scancode feature and then start preparation of the release.
But regardless of official release, there's really nothing standing in your way of using the SFML 2.6.x branch.
The 2.6.x branch is as stable as it gets, so unless you're waiting for the Scancode feature, don't just wait for an official release to switch