As we await an arbitrator's ruling on a fourth option year for Lewis Thorpe, it sounds like some similar decisions are coming down, not granting the fourth option.
In case you missed it, Thorpe and a few other players would be eligible for a fourth option year in 2021 under a strict reading of the rule that a "full season" must be at least 90 days. Usually this rule only applies to rookie league seasons and seasons missed due to injury, but 2020's unusual schedule was technically shorter than 90 days too. So the players and teams have taken these cases to an arbitrator.
MLBTR reports that the Nats lost their claim on a fourth option year in 2021 for Erick Fedde, although his situation was a little different than Thorpe's (Fedde had a 4th option for 2020 that the Nats didn't use, keeping him in MLB for the entirety of the shorted 2020 season):
But the St. Louis beat writer suggested on Twitter that the same ruling will come down for the Cardinals' Justin Williams (who is in Thorpe's same position):