This rating is not "expecting" anything. This assessment is accurate, it IS left leaning and mostly factual, with unlabeled opinion pieces... What is the problem with identifying that? All news sites are biased, it's just how it is
Rating it as though they’ve published something that is untrue (what the average person expects from a factuality rating) when they explicitly haven’t failed fact checks is stupid AF.
If you sell opinion pieces as news then yes, that's not truthful and a completely valid criticism as people could misread it as actual news.
You should rather ask why they did not fix this yet, which would not just improve their rating quite a bit, but also be an overall improvement for the readers and the overall concept of sharing information (and it is trivially easy to do so too).
Crying about that feels rather weird and like agenda pushery.
So factor that into the bias rating, not the factuality rating, because that is about bias and not whether or not they have published things that are untrue.
So you're saying I'm right because an opinion is an opinion and not true or untrue.
If it’s not untrue then it shouldn’t affect the factuality rating, not sure why this is hard to get.
Incidentally as another user pointed out in this thread, LGBTQ Nation does label their opinion pieces as such. Until MBFC presents evidence otherwise, I’m going to conclude that what they have deemed “undisclosed opinions” are things like “trans kids exist and deserve protection”.
Again, I think the average person is going to see factuality rating and read it as “how much of their reporting is true or untrue” and not “what amount of their reporting could potentially contain opinions according to the guy that runs MBFC”.