You are correct in that Rendemption.
When I made the guide on how to recruit Minthara in Update #5 it took me by surprise to see just how many players interested in recruiting her were completely new to the game and barely even got past the Grove not even knowing that knockout exists in the game. So yeah, unfortunately everyone new who tries to recruit her now will immediately get spoiled about who the Guardian and the Absolute are, along with the fact that a *certain Gith* is alive.
Personally I'm more angry about the fact that this bug ruined Minthara as a character entirely with Update #6 since it's overriding all her comments throughout the game and I doubt there's going to be a hotfix for this mess, because unlike Astarion who gets 3000000 threads per minute for every damn thing in existence, Minthara is constantly overlooked and barely acted upon with legitimate feedback being provided. So it's probably going to be a whole month of this, or whenever Update #7 comes out (assuming it even bothers to fix this).
It took me literally 5 minutes from starting a new game and getting to Moonrise in order to test Minthara entirely once the update dropped (via Sorceress bunny hop), so I'm quite annoyed that a character crippling issue like this manages to happen to a character that's already broken as hell and has been ever since release.
It's unacceptable to me that Minthara for 7 months now still isn't functioning properly, still doesn't have her content optimized at all nor has all her content available to the player.