How much more secure would their business be if they're at the mercy of Monopoly supplier with no competition?
At least Apple's business is protected as they're a value-added supplier with a near impenetrable network monopoly to prevent competition, but most of Intel's business is chips, conceding manufacturing of them to a single supplier who's now worth nearly 2x Intel, who are big enough to buy ARM or merge with AMD seems unwise for their long-term prospects.
Rather, if they have fallen behind on manufacturing (which they have) and decided that they need to access TSMC fabs (which they seem to have) then the priority should be x86 not Ponte Vecchio.
Why? Because whilst they are behind on process some firms have an bigger incentive to switch to ARM (eg Apple). Once they have gone to ARM they are much less likely to come back to Intel x86. If they can keep them away from ARM they have a chance of getting them back if/when they get their manufacturing back on track.
Reading the earnings call I think its reasonably clear that they will be going outside for at least some of their manufacturing - the 'contingency plan' is really around what happens if things get worse.
If the x86 based product falls behind customers have an incentive to move to ARM made on TSMC (Apple being the obvious case in point). In this respect AMD is doing Intel a long term favour by giving firms an x86 fall back.