These kinds of odd gaps in the discography weren't uncommon during the quad years. Carly Simon's debut and No Secrets got done, but no Anticipation (though two cuts did make the Best Of comp in quad). Deep Purple is another example, after Machine Head they skipped Who Do We Think We Are? (which had "Woman From Tokyo", one of the band's biggest songs) and Burn - the MK III lineup's first and most successful (I think?) album - in favor of Stormbringer.
It wasn't just WEA, the trend shows up at CBS as well. Sly & The Family Stone's Greatest Hits and Small Talk were done in quad, but the two albums in between - There's A Riot Goin' On and Fresh - were skipped. Same for Blood Sweat & Tears: after the self-titled second album and Greatest Hits were done (but not III & IV), there were no quad releases until Mirror Image (though we found out recently from the Sony 360RA releases on Tidal that 1972's New Blood was mixed and left unreleased).