Most of the 10,000 calorie challenges on Youtube are not done by people trying to lose weight. If your goal is fat loss, eating an excess amount of crap one day a week will not be outweighed by restricting the rest of the week.
For me, dieting and weight loss is all about balance. I incorporate a cheat MEAL once every two to three weeks. I agree with
mattierocks that a weekly cheat day , or even cheat meal is counter productive and can develop a bad habit and relationship with food. I would never recommend doing an all out cheat day where you eat garbage for a full day. But if you want to go out and have a few slices of pizza with your friends every few weeks it won't ruin your progress. Just make sure you are eating in a deficit and staying consistent with your calorie intake and workouts.
Definitely wouldn't recommend an all out cheat day every week though, you will not see the results you want on a diet like that.