You’ve apparently been reading some false propaganda.
Arthur’s sword is called Caliburno, in the dative case, presumably representing a nominative form Caliburnus in Latin in Geoffrey of Monmouth's “Historia Regem Britanniae”. See http://www.yorku.ca/inpar/geoffrey_thompson.pdf and look for “Caliburnus”.
In medieval romances it usually appears as “Caliburn”. In later romances it often assumes the enhanced form “Escalibor”. Sir Thomas Malory renders it “Excalibur” in his “Le Morte d’Arthur”. Your phrase “ex calce liberatus” has nothing originally to do with Arthur’s sword.
The earlier name of the sword may be its Welsh name, usually modernized into modern Welsh as Caledfwlch, and appear when copied directly from a medieval manuscript as something like Kaletvwlch. The name may be identical with that of Caladbolg, the sword of Fergus mac Leide and Fergus mac Roch in Irish tales.
The story of the sword in the stone appears first in Robert de Boron’s “Merlin”. All other versions are obvious copies or adaptations. And Robert doesn’t identify it with Caliburn, though he says nothing against such an identification. One sequel to the “Merlin”, a work called the “Vulgate Merlin”, identifies “Escalibor” with the sword in the stone. But another sequel, sometimes known as the “Post-Vulgate Merlin”, claims that Arthur received “Escalibor” from a hand in a lake, aided by a Fay, Most accounts that mention “Caliburn” or “Escalibor” don’t indicate anything about its origin. It is just Arthur’s sword, or sometimes Gawain’s sword, not in any way obviously symbolic. The “Vulgate Merlin” explains that Arthur gave the sword to Gawain when Gawain was knighted.
So I certainly don't think that Excalibur represents TRUTH removed form the ROCK, except possibly in some allegory you or your source have invented. I think, that in all tales that have come down to us that mention this sword, Kaletvwlch/Caliburn/Escalibor just represents itself, a powerful sword in legend which is possessed by Arthur and Gawain and was according to Geoffrey of Monmouth forged in the faery island of Avalon.
Sangreal “royal blood', is a name found in Malory’s “Le Morte d’Arthur'' for le “Saint Graal”, the Holy Grail, presumably a spelling of the actual pronunciation in some speech. It seems quite fitting, as the Holy Grail is supposed to contain Christ’s blood according to Malory’s version.
But what else Malory and his sources say about the grail doesn’t fit your allegory about “we” being the chalice containing Christ. Where does that come from. Did you copy it from somewhere or just invent it?
Attempting to prove religious matters requires more than sloppy allegorizing about material that was not written as an allegory.