It's far from clear whether SACD2 discs will play in SACD1 players. It's very possible they will NOT, because the upgraded copy protection will have to depend on something in the player. If SACD1 players can play the new discs then there's no added security.
So: your new multi-thousand $$$ SACD players may be useless with the new generation of discs.
So: your new multi-thousand $$$ SACD players may be useless with the new generation of discs.