BMB has refuted this, or at least alluded that they are entirely separate ideas.

additionally, from TOOL NEWSLETTER AUGUST 2013, E.V.:

...to answer those email questions about any contention between the supposed hidden track, “Problem 8: The Riemann Hypothesis” and the “Bethlehem Abortion Clinic” record in the spoof catalog in the import release of the “Aenima” CD, I can tell you unequivocally that there is NOT (other than the obvious). And as for the name “Volto” being an anagram for “Tool V”, although technically it is, this is merely a coincidence…