They may still do. This deal is far from settled, I guess. It wouldn't surprise me if ARM's licensees are joining up on video conferences these days, discussing how to protect their interests.
Some thoughts:
I find it hard to believe Jensen spends $40B+ to get into a low-margin licensing business. I can see the argument that he may be spooked by AMD's "Radeon Everywhere" drive; in particular the deal with Samsung around Radeon IP in tablets and mobile phones. Getting control over the ARM ecosystem, as some here have suggested, may let him shoehorn GeForce into the mobile space. But spending $40B+ to achieve that seems to be an expensive way to go about it, with no clear route to big profits and payback.
My take on the motivation for the takeover is that Jensen wants to strengthen Nvidia's position in the data centre. Nvidia's lead in AI/GPGPU and rapid revenue growth in this space are the main reasons for the lofty market valuation (recently passing Intel's market capitalisation to become the largest semi-conductor company in the world). There is a lot of hype driving the stock, about AI and data processing from the data-centre to the edge (last hop on the Internet before the consumer), where shareholders bet that Nvidia will lead, and thus produce large profits in short order.
However, Nvidia needs world-class server CPU capability. Intel has stumbled badly recently, and Nvidia was forced to switch to AMD EPYC in their flagship DGX A100 server. That is is a brittle and embarrassing situation. To end the dependence on a competitor that has "A+A" (AMD EPYC CPU + Radeon GPU) as its competitive goal, and with Intel now also having comprehensive AI and GPGPU ambitions, Nvidia needs server CPU capability urgently, to stand up to its data centre competitors long term.
ARM is now the immediate challenger to x86, and they have an aggressive and promising roadmap for attacking the server space (a few years ago, when Jim Keller was enthusiastically working on K12, AMD's high-performance ARM processor, ARM stood on stage with AMD proclaiming 20% data centre share for ARM in 2020, which reflects the scale of their ambition, if not execution). To leapfrog Ampere, Nuvia and other promising ARM server CPU upstarts and efforts, taking over ARM makes sense. Jensen may be willing to spend big to jump ahead, and getting ARMs excellent CPU team and server roadmap will let him hit the ground running. This can clearly be worth $40B+, if it takes Nvidia into the lead in the data centre and keeps AMD and Intel at bay, while — if panning out as promised — the AI revolution ushers in a new era of high-performance computing.
But then there is all the competitive issues with the ARM licensees. As concerned ARM founders express, there is a real threat that Nvidia may undermine competitors and completely change ARM's current open and fair business model. But, unless Jensen wants to spend years in litigation, I guess he has a solution to this conundrum; perhaps a licensing division operating independently, perhaps with a stake for the biggest licensees; perhaps a consortium of sorts, that can protect the interests of licensees and cooperate on shaping the future of the ISA.
PS. Note that ARM licenses more that just an ISA, such as interconnect and other SoC IP (e.g. see their
System IP).