I think OP is using the wrong term - breaching terms of contract is not illegal in itself. It just means Oracle will not do any more business with you.
Breaching terms of contract is most definitely illegal and Oracle can sue any time they want. It's not like trademark law, where you _have_ to sue even if you don't want to; Oracle can ignore anything that comes out not looking bad for them, which still being 100% able to sue the pants off of anyone that goes "hey look this product is worse across the board in real world comparisons to MySQL and MariaDB".
They can sue but it's not illegal, and they very well may not be able to get any money from you for truthful statements.
So what you're saying is that sysadmins should all benchmark Oracle products to prevent their employers from being trapped in Oracle land?
makes sense. so unless they dedicated the resources to figuring out who did it, etc. it's reasonably moot.