A canceled my Prime, so I can't verify this... it looks like they are still there.
They were reportedly being removed Feb 7, but that seems not to have happened.
According to Reddit, it may only be leaving for some geographies... India has been mentioned. For some reason no one has replied to the Reddit thread after Feb 7, which is peculiar.
Forbes says some Prime customers have gotten messages that The Expanse Season 1-3 are leaving, but it being Forbes, the verification is spotty.