I see. So if they can disconnect you from everybody else (for example, if they control the internet connection you're connected to), you have no way of telling whether they're replaying IPNS records to you.

The traditional internet solves the problem of not being able to trust your internet connection (say, in a coffee shop) with public key infrastructure so that the most a rogue internet provider can do is DoS you (they can't get a certificate for google.com and TLS is protected against replay attacks), so this sounds like a downgrade in actual security.

I think it's a bit unfair to pretend that TLS replay would be the same as having a not entirely updated IPNS record. The threat models are very different.

The corresponding attack against IPNS would be if the attacker could make your perspective of the world go backwards, and that is prevented by the sequence number.

Indeed, but TLS doesn't have the problem of replay at all (we hope), so IPNS is by design susceptible to a threat that the traditional internet is not in the case that your connection is untrusted.