Chekov might have been a more interesting choice, especially since gay people are treated like crap in Russia.
If there is a third film, they will have to decide whether Chekov has transferred off the ship or recast the part. They could go the route of the animated series, (which Chekov was not in) and bring in a new alien face or two. All the other alien crew members, except for Scotty’s little buddy, have been essentially in the background so far.