The only senses in which I can imagine the phrase "come true" being used when discussing anything other than predictions or dreams is in relation to
A: Breeding plants and animals and
B: In the discussion of materials which distort under some conditions but return to a straight shape when the conditions change.
For example I can imagine
A: That breeders might say, after a long period working on a new breed of animal or variety of plant that it had "come true" in the sense that examples of the animal demonstrate the desired characteristics reliably when both parents are of the new breed or that plant does the same when the parent plant is self-fertilised or fertilised by another example of the variety.
B: That a woodworker might say that a piece of wood (perhaps a door) which had warped when it got wet "came true" when it dried out.
Even if these expressions are used (and I have no evidence that they are) they would be technical ones and not of the same nature as "a dream come true".