It isn't ironic, that is the whole point of a Market for Lemons, the inability to distinguish a good product from bad before purchase due to asymmetric information. That is why I think the author makes a mistake saying that it has no relation to enshittification.

The ultimate problem here is that MZOO's incentive to maintain their level of quality isn't very strong. There is little preventing them from slowly make their product cheaper and cheaper until they are delivering the same quality of those other brands. That would be the same process as enshittification. The primary difference is that enshittification can happen for other reasons such as a monopoly while a Market for Lemons is specifically because information asymmetry.

MZOO might be good now, but the economic incentives suggest they are just in the first stage of this process. It would take an owner committed to quality to not succumb to those incentives and it's impossible for us to know if MZOO has that type of owner.