It meant that Lyse wasn't actually a member of the original Circle of Knowing or an archon since the tattoo wasn't real so the writers could have a valid reason to have her leave the main cast as of 4.0 since she and Papalymo were sidelined after 2.5 and it seemed like they were trying to thin the cast anyway.

"Yda" only worked as a character against Papalymo and they were very reliant on each other as a duo. With Papalymo gone and Yda actually being Lyse, they also had more opportunity to expand her character when she was a part of the main party in 4.0.

Also, 1.0 characters did meet the original Yda.