Real OP_RETURN limits requires a fork. It should be enforced by the chain rules.
There, I said it.
Discussion
Yup
This is worst case scenario. Only if core is successful in transforming Bitcoin into another ethereum. Humanity needs uncorruptible hard money. I still think Bitcoin is our best hope for that but only if we can defend against attacks like this current one by compromised core devs. If money takes a back seat to other use cases then unfortunately it may become necessary.