There are some common usage conventions but the limits described in this article are completely arbitrary.
The title is "Stop using JWT for sessions" not "Stop using JWT".
The arguments against JWT themselves are wholly separate: https://paragonie.com/blog/2017/03/jwt-json-web-tokens-is-ba...
If you want to say that client sessions should not be 100% on the client side and should be split between client/server then just say that. There are pros/cons but at least that is a clear argument instead of misleading about JWTs.
I don't even see why you believe this to be the case. The article (and the follow-up) are both pretty clear about what the actual issue is.
Did you read them or just react to the headline?
I think you can also see from my other comments that I know what I'm talking about and my issue is the fact that * instead of discussing client/stateless vs client/server shared state*, this article spreads more misleading information about JWTs and sessions.
Otherwise, they could just use a long random string and maybe HMAC it and call it a day.