I'll post this again:
Per Jen McCaffrey, The Athletic:
Following the season, Story had no elbow problems, but when he ramped up his offseason workouts and began throwing just before Christmas, he started to feel pain in his elbow. Story visited a local orthopedic doctor near his home in Texas before flying to Boston to get the elbow evaluated by team doctors. Both groups decided the internal bracing surgery was the best option.
If Jen is accurate, the issue was NOT KNOWN BACK IN OCTOBER, IT WAS NOT KNOWN UNTIL MID-DECEMBER.