Satoshi was still acknowledged in Gou though, even if he has been heavily downplayed. It's different from Saikoroshi not getting acknowledged by the script at all.I really don't see it weird given how Gou handled so many stuff. I mean, Satoshi is super important to Satoko and extremely connected to the Syndrome and yet it's like he stopped existing in post Matsuri timeline, so I don't think a lack of any real Saikoroshi (Except the first ending, the scene with the bicycles) mention is odd with the kind of narrative Gou has created.
Of course, the scene in Kai is still when she's trapped in the loop so it would make sense she'd disappear. But there are more scenes once the loop is break.
She saves Takano as a kid after the story ends so I'd say she definitely her own person with her own body that exists separately form Rika. If we want to assume Saikoroshi as non canon (I disagree) it definitely shows R07's original intention. Both the anime and even the novel described the girl who saved Takano as a tall adult woman which Rika is not but Bernkastel is (Pre PS3 art retcon of course). Of course you also have this:
The epilogue itself doesn't need to be erased, it could just happen in the "future" from now.
That's kind of what I'm saying though. I think Rika is getting called cat because there's no separate Bernkastel character yet at this point.I definitely don't feel like she's talking about anything but Rika's past experience at this point.