Based on how things seem to be setting up for 2026 I’d wager it’ll either work at all or work at only the home park.
It doesn’t make any amount of sense, IMO, to maintain a special ‘legacy only’ mode in the new unified system for only one pass type. It just doesn’t. That said - doesn’t mean they didn’t do just that. I’m just saying it’d be way easier to just add the IDs for membership as is across the board. Less effort. Less testing. Less to go wrong. More customer satisfaction when everything just works everywhere. They’d actually have to expend effort to make it work only at Legacy Six Flags after the system is unified.
Long story short I suspect that they’re wrong about this.