The film was shot on 35mm film, so its proper resolution would be 4K. However, there are many factors to consider. Is it a new DI (digital intermediate)? Highly doubtful but likely necessary as most DIs are distributed to both cinema and home video platforms in 2K. One would have to do some research regarding the Trek films.
In the end, the resolution is not nearly as important a factor as most people think, especially if one is viewing the image on a screen smaller than an 80" 16:9 form factor from more than 4 or so feet from the screen. Far more important (and more relevant for the new "UHD" standard) are a wider colour gamut that more faithfully approximates reality (current Rec. 709 is roughly 35% of reality, proposed likely P3 gamut is, IIRC, approaching 60% and Rec. 2020--not yet available in any consumer gear, nor likely to emerge in under 5 years in such gear at affordable prices--yields about 85%, IIRC); a greater dynamic range in contrast (currently marketed as HDR, a feature coming to both media and displays sometime in the next year, but not currently available across the board with UHD displays today, and impossible for any displays manufactured before this summer); and sufficient processing power to avoid excessive image lagging, as well as providing decent upscaling of non UHD material.
