Self Deprecation
This was a change that was completely unexpected. No one but the most powerful could feel what Primus had done, but it made them just as confused. They didn't know what was happening, and obviously Primus wouldn't be explaining it to them either.
Eska's expression changed somewhat, but she soon calmed down. She had an understanding of the situation that others didn't, so she could easily guess what had happened. She hadn't thought enough about the matter to guess this ahead of time, but now that she had, it made perfect sense. Primus had no reason to risk his chances of completing the Cycle of Karma just to allow Ryu to enter a place that was insignificant to him.
He obviously didn't care about Ryu's progression or how far he would make it. Maybe in Primus' opinion, just having him follow him around was a great boon for Ryu and he was actually trying to waste it.