You need to know the different between ISA and microarchitecture. The portion affected are the cortex cores, or microarchitecture, Huawei claims to have completed an inhouse core. For ISA, they are basically instruction code formats like C++ etc. So with a perpetual license, ARM cannot win in courts even outside China.
The world doesn't work like that. If trump wanted to do that, he would have done it. He is using it as a tool to negotiate. It is also hurting US, he is betting US can withstand this hurt.