What about in 5 years? riscv isn't competitive at the top end but it's closing in fast.

Huawei is probably the one that possibly might move away from arm because they have their own operating system. The US could tighten their controls more and ban them from arm altogether- so far they are prohibited from arm 9.

I am not sure Huawei would go for riscv - they could easily go for their own isa or an arm fork.