Someone thought its was a good idea to put a 2×4 in the door to keep it locked.
But, it will also do a good job of keeping people in during a fire.
If it is dark and people are panicked, that board could cause some big problems.
The board very easily could prohibit people from getting out in an emergency. If you see this, look for other types of locks on this door too. If they are willing to put a board in there, they have also tried other methods of locking people in.
Remove the board and explain why it is dangerous. Be aware of these types of issues on inspection. It could make a huge difference.
Stay safe and take care.