Weird thing to do. I don't actively follow Madeline but the few things I've seen posted from them here have been generally solid. I can't speak on whether Madeline has much expertise on the DPRK, but also that's not necessarily something to hold against someone.
Most people "don't know anything about the DPRK". It is a topic that is notoriously difficult to get reliable let alone comprehensive information on. Even most MLs don't know that much about the DPRK, about its daily life, how the system works exactly, etc. This isn't their fault, it's just the reality of the extremely anti-DPRK propaganda environment that most of the world lives in.
Don't get me wrong, if you really invest the time and do the research you can find enough to educate yourself on the topic, but even then it's still easy to make mistakes. So i'm not going to say someone is a bad communist if they are not an expert on the subject of the DPRK, as long as they maintain a positive orientation toward the DPRK and don't repeat obviously malicious propaganda nonsense about it.
In my opinion the best policy to take would be to allow Madeline's videos to be posted and if they contain errors to address and correct them. That would be an excellent opportunity to take to educate people about the reality and dispell some myths. Why adopt this closed-off attitude against someone who, by all appearances, seems to be a well-meaning comrade?