There are many examples of MrBeast using his own crew and claiming they are random subscribers. You can use the website MrBeast Wiki to find all of the people that have participated in his video and if they work for him.
More Allegations against MrBeast
Adam- Far Right who is a part of the Beast Philanthropy team has appeared in 5 different videos claiming to be a random subscriber.
Two videos he is in:
1) Anything You Can Fit In This Triangle will pay for
2) Extreme $100,000 Game of Tag