Perhaps the greatest impact that Yelchin has made on the Star Trek franchise is the fact that even with the fourth film in limbo, his Enterprise crewmates still think of him when discussing the process of getting another film into the air.
However, as seen in the fandom that Anton Yelchin had acquired over his time in that role, as well as in numerous other projects like Fright Night, Green Room, and Thoroughbreds, his performances were strong to the point where that fear was unfounded.