You will need an external Blue-Ray drive that is capable of playing 4K content if attempting to rip a 4K disc. No software of firmware will turn a non-4K player into one. Keep in mind that 4K and 4K UHD discs are different and require a drive capable of playing said formats.
You will need to hack the drive's firmware in order to rip the disc due to additional copy protection found on Blu-Ray discs. Not all drives are supported by the hack. Some discs require even more hacks in order to rip them (a much more complicated process). Some discs literally cannot be ripped at this time due to enhanced protections in place. Some audio codecs may require conversion in order to even be ripped. So not always a 1:1 conversion once ripped in order to be playable.
AppleTV by default, won't play MKV files natively. You will need additional software to support that function. Plex will play MKV files as it is "additional software" by definition. Other apps are available to play said content. Most are not free, however.
Look up LibreDrive on the MKV forums under optical disc drives for more details. This is only just one hack out there that will be necessary. In some cases, your drive will need to be converted to region 0 in order to play the discs. Some discs which are sold are not clearly marked as to which region they are for, and you end up with a disc that cannot be played without hacking the region code on the device first.
I recommend making a post on the MakeMKV forums about your specific Blu-Ray purchase before doing anything as they may be able to tell you whether the discs have added protections that cannot be bypassed. Since this is a pre-order, it may be too soon to know if they are rippable as someone will have had to have ripped it first to know for sure.
