With respect to the “mystery” Star Trek project that Meyer is now working on, the only other major Star Trek movie and/or TV-related project known to be in development right now is Star Trek 4, the followup to last year’s Star Trek Beyond (itself, the third installment in the Star Trek movie franchise reboot timeline, aka. the Kelvin timeline).
Nicholas Meyer has confirmed that he is actively working on a new Star Trek project, in addition to the upcoming TV show Star Trek: Discovery.
The filmmaker himself is well-renowned within the larger Star Trek fan/Trekkie community, having directed both Star Trek II: The Wrath of Khan and Star Trek VI: The Undiscovered Country, in addition to having co-written Star Trek IV: The Voyage Home – three of the more widely-acclaimed movie installments in the franchise to date.
As mentioned, Meyer is now serving as a writer and producer on CBS’ Discovery TV show, the first Star Trek TV series since Star Trek: Enterprise premiered back in the early 2000s.