Locked notes with Device Passcode not viewable?

I received this warning (pls see screenshot) when attempting to enable the feature. Does this mean my old 2012 MacBook Pro won’t be able to view locked notes at all, or will I just be forced to unlock them on the 2012 with the old, original password?

I rely heavily on Notes, and have three devices in total that I synch them across. I’d love to enable the new shorter passcode feature for my newer devices, but will pass on it if old ones can’t see access certain notes. Thanks!