Apple can make one enterprise foray. Apple can design an "m1" chip for datacenter/server. AWS already doing it for their own servers. Apple shown us they are capable of design a good chip based on ARM. Apple can take their chip design to the enterprise market.
Considering MacOS seems to be an aging spaghetti-BSD under the hood, there's no doubt any serious attempt at the server business would come with Apple submitting patches and documentation to major kernels like any other chip company. AFAIK the M1 architecture can be targeted by Clang and GCC and some people have reversed engineered support for the Linux kernel[1].
> Their own chips may go into servers but probably just for in-house use/services delivered to customers.
Hetzner is already renting Apple M1s[2] ! It was on HN not too long ago. Although it seems aimed at devs who need to test against that environment.
[2]: https://www.hetzner.com/dedicated-rootserver/matrix-apple