Do take note that in the build 10565 announcement, Aul did mention that both Russian and Turkish language packs will be unavailable until “later this week,” so it remains to be seen whether this has changed, or will the two language packs sit out from today’s rollout.
Also, the Insider builds does support additional regions other than the ones which have been officially documented, thanks to the recent addition of Australia, Canada, Japan and India, while there is still a bunch of other countries in which Cortana remains unavailable. Microsoft has also mentioned that “Later this year Cortana will also be available first to Windows Insiders in Brazil and Mexico, and in French in Canada.” [Press Release]