More likely they were mastered in Japan from the tapes sent by Reeves for the 24-bit reissues that appeared in Japan (I have a few in lp-facsimile edition, don't know if they were ever in jewel box) earlier than 2011, before the Impulse Album boxes were released. . . .Or that would be my guess.
Anyway, not knowing if the Japanese tweak things for SHM-CD mastering or just do a straight transfer to the SHM-CD process, I DO find that I hear differences between SHM-CD and other pressings. Maybe it's system dependent (I have a killer transport) or maybe it's just my imagining, but more often than not there's a "less digital" sound to the SHM-CD in cmparison for me.