While you might be right, I suspect there will be some years of people doing chips in both ARM and RISC-V to trial balloon it and see how it goes. Most customers will already have ARM toolchain they'd just prefer to stick with.

But if it works out for them, I think it will be far more than a marketing play. Having control over the ISA and dropping the license fee while still getting access to industry standard toolchains, is too tempting.

ARM would not have gotten a $50B+ valuation if the license fee was seen as not a big deal.