This guy in MPC Forums took a picture of MPC Live which he bought from Guitar Center:
http://www.mpc-forums.com/viewtopic.php?f=48&t=181995&start=120
The proof…
“In stock and ready to ship”
http://www.guitarcenter.com/Akai-Professional/MPC-Live.gc
As for the X according to this seller…
Pre-Order Available In April 2017 will ship out upon release of product. MPC-X will be released near the end of June.
edit*
Also another MPC forum member got an email from Thomann saying they have a shipping date for the first bunch, 12.05.17, which can serve all preorders. Next shipment will be 31.05.17
http://www.mpc-forums.com/viewtopic.php?f=48&t=181995&start=180