Nothing needs to be "proven in court, before playing any such cards." It needs to be asserted. Once asserted, there may be a cure period (the licensee might have 30 days to remedy the problem, otherwise the contract terminates).
The party may disagree, and could negotiate different remedies or timelines - again, no court is required here. However, if they can't come to terms, then they can pursue this in contract court.
Be aware that I'm not defending, or justifying, or taking a position on any of this. It's just how it is. If you don't like it, then work on reforming tort and contract law as opposed to stating on Hacker News that the basis of most worldwide commerce is "nonsensical."
None of this is criminal law. It's contract law and it will be dealt with per the laws, procedures, precedents, customs, and traditions of civil jurisprudence.
that is something that has to be proven in court, before playing any such cards
If that is the case and you defend it, then this is a very unique situation, where law is not enforced by state institution, but by Google, Apple and Amazon. The question is what law? As clearly it is not US law.
If there is breach to the law, then there should be article Nr of breached law, otherwise all of these arguments are nonsensical. Nowhere in the world - even in Saudi Arabia it is possible to be judged and sentenced by unwritten law - by nongovernmental entities. Otherwise it is unlawful lynching by mob and there are countries that allow those, but US kinda positioned themselves as a country that guarantees The Law. Now that guarantee does not work.