Voluntary still means you can show up, or not ... Remember it was just 420.
If Cook thinks not showing up for voluntary workouts will get Beane to flinch and give him 15M per, have at it, it won't work.
When Davis was drafted last year I guessed he'd be the starter in 2026, then of course Cook had a career year. I still think Davis will be the starter in 26 and they'll draft his replacement next year. It keeps you on the not paying a RB past initial contract path.