Most likely it will not happen. They are moving away from transport based players. They feel the future is in the DS products and I have to agree with it.
The CD12 has not been made for a few years. Your best bet for a Uni Player will be a Unidisk 1.1 or get a used CD12.
Linn has no plans for a Uni CD12.
And after you've listend to a DS you understand why. I was also sceptical in the beginning, but even a Sneaky DS is more musical than an Akurate CD/Uni 1.1. The latter sound more impressive, but the Sneaky clearly has better rhythm and timing and presents the musical message more convincingly.
I never found SACD a musical improvement over CD. It was a dead end. Studio Masters, on the other hand, are more musical and much better sounding than ripped CDs (although not quite as good as good vinyl). It's a pity so few are available yet.