Still I think I’ve only seen Warner Brothers offer MOD Blu-Ray. But a lot of MOD releases are on burnable discs, and those discs are not as compatible with players as VHS in the 90’s (The last MOD I bought, I noticed that Warner Brothers has put a warning on the DVD case saying that it may not work in all DVD players, recorders and computer drives).
Also with MOD a lot of times the studios use whatever Videotape master is available. (The 1989’s “Superboy” Series I remember that when I watched the entire series a few years ago on DVD, I found the quality on Seasons 2-4 varied from looking like it came from Digital Betacam all the way down to a VHS copy being used as a master), So for HD, they might use a master that was prepared for the Japanese MUSE system in the 1980’s or HD Laserdisc in the early-1990’s. But at the same time, for modern shows, the master may only be in 1080i or 720p HDCAM/SR as that would be the resolutions and format that TV stations and networks would want for HD broadcast. (There might be a 4K, 1080p or film Master somewhere, but the closest/easiest one might be the lower resolution. Also, 4K videos on iTunes or YouTube or other streaming sites usually have bitrates in the 35-45 Mbps range, while 4K Blu-Rays Need bitrates between 50 & 100 Mbps, but for broadcast TV networks require bitrates in excess of 200 Mbps.)
So the question would be does the source work for Blu-Ray and would people buy it? I don’t know about you, I don’t know of too many Blu-Rays encoded at 720p or 1080i.