Raze had made it clear to those that knew the truth about him. That he was going to leave and if anyone wished they were free to join him.
Liam and Safa had already decided they were going to come regardless of what had occurred.
They had their reasons: excitement, closeness to Raze and everything that they had built up was because of him, so they felt like they needed to finish the journey with him.
Then there was Dame who had similar reasons. He was fine and somewhat expected that they might want to come.
There were those he was taking back to Alter, like Charlotte but wouldn't necessarily be continuing the journey with him.
So he thought that was it, until Beatrix had made this suggestion. She wasn't from Alterian, she wasn't with Raze the entire time, only partly the end of the journey, what reason could she have for even wanting to go with him.
