It looks like Nvidia's AIB partners have already been notified about the upcoming GTX 11 launch schedule. First to launch will be the GTX 1180 flagship at the end of August. Then after 1 month the overclocked GTX 1180 cards will be launched along with the GTX 1170. Late October will see the launch of the GTX 1160 and the mobility variants will most likely come in late November.
https://www.notebookcheck.net/Nvidia-GTX-11-series-release-schedule-already-sent-to-AIB-partners.317826.0.html