If it finds any potential wrongdoing with both companies, the CMA could simply block the deal, especially if it thinks the deal will break any antitrust laws.
Prior to its acquisition, ARM was a standalone chipmaker, supplying its chips to other major tech giants, including AMD, Qualcomm, Samsung, and Apple, to name a few. When NVIDIA stepped in, it said that it will not hamper ARM’s relationship with those companies and continues with the latter’s “open-licensing model” and customer neutrality.
Of course, none of it detracts from the fact that NVIDIA as a major brand could and would try to establish something of a monopoly on the world’s supply of microprocessors. Seeing how it is in a prime position to do something of the likes.