It's convoluted because of the potential lockout. Any player on a 40-man roster would be ineligible to play in the minor league during an MLB lockout. That's related to the MLBPA, and has nothing to do with option years.
Once any potential lockout is settled, then option years would work just like normal and Walker Jenkins still has 3 option years remaining, so he could theoretically be optioned to AAA during the 2027 season (and two future years)