There's all kinds of funny little sub-rules regarding minor league options. Yes, people do risk being fired for not being on top of these and other rules. And I'm just a layman and could be misunderstanding a detail in the following synopsis.
Each year's option covers the entire season, down and up and down again. He was already up and then down with the Red Sox, so they must have exercised his option for 2026; the Twins piggybacked off of that. For any given year, the option can be invoked a limited number of times (5). But the interesting little exception is that if a player is down for only a few days (at most 20) the option isn't exercised. It covers cases like this where someone's brought back up due to injury to another player.
So, either way, I'm pretty sure Anderson has the two remaining options that he arrived in Minnesota with, that can be used for two future years.
One last thing. I could be wrong but I think all of Cole Sands's time at AAA in 2026 has been on injury rehab. That does not count as burning an option. His latest rehab time had run out, and the Twins had to either call him up, option him to AAA, or I guess put him back on the injured list. If the player is saying he's good to go, you can't just do that third option. So they put him on the 26-man and let him prove it. He bombed, and I guess is willing to go on the injured list again as a result. Bottom line: this maneuver may actually have preserved Sands's one remaining minor league option. For whatever that's worth. Go figure - it's possible the FO knew what it was doing with regard to the rules. (Whether it was wise - they won the game Sands blew up in, so I guess it worked out.)
Fun stuff, I know. 😄 Anyway, even if it was a rhetorical question, you asked.