No, it's not an absurd claim. Lattice key establishment goes back into the mid-1990s, and was at one point a serious contender for the alternative-to-RSA/FFDH algorithm that ECC became. Modern LWE lattice KEM is approximately at the same point in its lifecycle (say, compared to original NTRU) as Curve25519 was to ECDH.
the McEliece cryptosystem goes back to the 70s, doesn't mean it's as well studied as RSA. obviously people study popular cryptographic primitives more.
having said that, I would trust McEliece more than Kyber.