Soft proofing CMYK in LR 5.2?

Question

ACR 8.1 allows CC users to soft proof in CMYK and LAB color spaces.  LR 5.2 will have ACR 8.2 capabilities, so will we be able to soft proof in these spaces as well?

Answer 1

What a shame.  The only book vendor option we have from within LR is Blurb, which uses CMYK printers and provides a CMYK profile for soft proofing.  The only way to soft proof with this profile, however, is to use Photoshop, but you then convert back to RGB when you return to LR, so thre is no point of going through that routine. 
Clearly Adobe recognizes the importance of soft proofing, and put that capability into LR.  Clearly Adobe recognizes that many LR users would like to produce books, and put that capability into LR.  Somehow Adobe failed to connect the dots and did not provide the capability to softproof book projects being sent to the only print vendor available in the book module. 
What exactly is Jeff's reply saying?  Jeff says it "won't" happen, which might mean that it could  happen, but for some reason Adobe has decided that having this capability in LR would not be beneficial to Adobe in some way.  I can't imagine how CMYK capability in LR would affect sales of other Adobe products, so that explanation seems unlikely.
Perhaps Adobe thinks that LR users would be confused by having the CMYK space available to use.  However, we have the option of chosing from among three RGB color spaces now, so how would a fourth space be a problem for us?  Besides, I don't think that LR users are less capable than Photoshop users (in fact, there is a lot of overlap), so if it can be understood in PS it can be understood in LR.  Hence, that explanation also seems unlikely.
Perhaps Adobe is trying to maintain a clear distinction between its "professional" products, which have greater techincal capabilites, and its, for lack of a better term, "consumer" products, which do not need to be so capable.  LR doesn't get CMYK because it is intended for customers who don't need it (although they send us to a book printer that only uses CMYK printers).  Of course, Adobe realizes that many LR users are professional photographers who have prints made in high-end print shops that use CMYK printers, just like Blurb does, so that explanation is just as unlikely as the first two.
Perhaps Jeff misspoke, and meant to say that it can't happen, not that it won't happen.  That is, that there is some technical reason why LR can't use the CMYK color space.  This seems very, very unlikely, although if somebody is aware of such limitations to LR, perhaps they could explain them to us.
The bottom line at this point, unless there is more information on why LR can't have CMYK capabilities, is that Adobe has made the decision, and that is that, and we have to live with it.  Sort of like the Creative Cloud.