Theory Crafting
The reception of the Dark Days Dungeon had been surprisingly decent when Jin thought that there would be a lot of controversy due to the difficulty of it especially for the 'normal' cultivators. For the fact that Jin had decided to keep most of its contents under wraps, most of the cultivators did not know what to expect and in fact, most of them went in with the expectation of being 'careful'.
There was no information available until you tried it once. Of course, if one were to look outside of the Pandamonium App circle, like social media and stuff like that, there would definitely be spoilers. However, a majority of the cultivators had unconsciously agreed that it was best not to spoil the fun of it.