Some thoughts on Losing the Peace (spoilers for the book obviously)

[Avro Arrow]

Technically, it’s not that they don’t exist - they were alive before the point of divergence that created the First Splinter, so they are theoretically still in existence after the timeline is undone. Just that they don’t necessarily intersect with the cast and crew as time goes on - The Dark Veil featured Christine Vale and Ranul Keru as part of the Titan crew, so conceivably Trys and Choudhury and Kadohata all are crew members in Starfleet, just not necessarily on the Enterprise.

IIRC, part of Kadohata's backstory was that she was part of the Enterprise-D crew back during the time of the TV series, so that should predate the point of divergence as well. Of course, there's no guarantee that she stayed with the Enterprise gang as late as she did in the First Splinter, but the history should still be there, so it could be a possibility.