Commercial 4K discs require Windows 10 and a Kaby Lake processor. There is only one real caveat. If you burn your own content that is not DRM protected, I suspect you can play it back via disc on something like this https://betanews.com/2017/03/07/pioneer-bdr-211ubk-bd-dvd-cd-writer-4k-ultra-hd-blu-ray/. But why would you do that instead of just playing the file from your hard drive? And when I deliver content to a distributor, especially 4K, these days they expect a hard drive with media.
For direct disc decoding you Mac lacks the required hardware even if you had a drive capable of UHD BD playback. And aside from lacking the hardware decoder there are some superficial barriers in place as well.
Honestly I wouldn't worry about it anyway. Even in 2017 1080p BD players (software) suck. If you are willing to spend some cash you can get some that are only mildly abysmal. And thats for standard BD, for UHD BD forget about it. This applies to PCs as well.
Its better, cheaper, and maybe even easier experience to rip the BD contents using makemkv, watch it via VLC and then delete it compared to just playing the disc some of the time. I don't believe UHD BD encryption has been cracked yet for ripping although once it is this won't require any special hardware (BDXL compatible BD drive).