In my personal opinion, the record labels that insist on only releasing surround mixes in box sets that include vinyl completely fail to understand the market for surround music. I would bet that the vast majority of folks that want vinyl LPs have no use for the surround mix, and vice versa. Releasing as a limited edition that quickly sells out just makes the situation worse.
This tactic has stopped me from buying the 'Tusk' and 'Mirage' Fleetwood Mac 5.1 releases, the Alan Parsons 'Tales' 5.1 release (which I still am hoping may get put out separately from the box set), and now this latest Opeth surround release. I would happily buy all of these if they were sold as standalone 5.1 DVD or Blu-ray, or bundled with just the CDs.
Agreed, except that stand-alone DVD-A/V discs were tried out for the first five or so years of the previous decade and have not made a comeback since then.
I also think that that stand-alone Blu-Ray audio discs are on their way out too as the amount of those releases have shrunk this year, so from here on out, I'm totally OK with bundling these types of discs together with CDs as I expect that's the only way many surround releases will ever come to fruition.