Yes expired oats are safe to eat as long as the oats do not have any bugs in it.
As long as the oats have remained sealed the oats are still okay to eat.
The oats won't be as fresh when they are expired but the oats are still safe to eat.
You should store oats in a cool dry place and keep the oats container sealed when you're not eating the oats.
It's best to eat the oats before expiration because the oats can lose some of the nutrition but they are still healthy and safe to eat.
Oats can keep for many years past the expiration date but make sure there are no bugs in the oats as sometimes bugs can get into the oats even when they are sealed.