As for the howler hortu, I do have a theory. I think it is an example of hypercorrection.
Educated Italians are conscious of the risk of amalgamating the fourth Latin declension with the second, because this is precisely what their own language has done. So they find themselves constantly typing "Sancto Spirito" and then having to correct it to "Sancto Spiritu".
So in this preface somebody hypercorrected the correct 'horto' to the incorrect 'hortu'.
In languages where the letter H is vulnerable, poor ignorant hypercorrecting people like Catullus's Arrius put an H in where it is not supposed to be. Similarly, in our own time, they are nervous about betraying their illiteracy by saying "Tom and me are going to the chipper"; so nervous that, even where "Tom and me" is required by English grammar (e.g. "he was very rude to Tom and me") they hypercorrect and erroneously say "He was very rude to Tom and I" ... ... poor illiterate things! They will even admit that they somehow can't get out of their minds the idea that "Tom and I " just "sounds right"!!! Such is the power of incompetent nannies and thoroughly bad teachers!! And the terrible, ghastly, desire to sound genteel! Better to sound Rustic than Genteel, sez I.
[Dorothy Sayers had a fine ... and amused ... ear for linguistic nuance. In 1933 (Murder must advertise) she offered, as from a cockney youth, "She is always telling tales on we boys"; and, as from a 'reception clerk', "Strictly between you and I." I wonder how much further this sort of thing can be traced back. In Have His Carcase (1932), Doris, whose "fundamental cockney was overlaid by a veneer of intense refinement", says "'It's not so easy for we dancers.'"]
I suspect that it was hypercorrection which led the old, correct version of a place-name five miles south of here to mutate, in the early modern period, from the historically and philologically correct 'Abendon' to the incorrect 'Abingdon' under the influence of all the other place-names where rustic tongues had carelessly modified -ing to -en'.
Theologically, a thorough-going up-to-date Bergoglian would, of course, have to change the final bit of that S Mary Magdalene Preface to "ad mundi fines, Israele scilicet excepto, perveniret". Sometimes, familiar phraseologies ... our automatic linguistic habits ... long survive changes which have happened in realpolitik. [I have noticed, as late as Dorothy Sayers (Strong Poison, 1930), Lord Peter Wimsey referring to "the three kingdoms" ... an anachronistic solecism, of course, since 1707.] Similarly, with all the old habitual formulae still potent just behind their tongues, Bergoglianists sometimes forget the Bergoglianist conviction according to which the Jews are not to be offered saving Faith in Christ our Redeemer. And they thoughtlessly continue to use, unmodified, *silly old outmoded biblical phrases like "preaching the Gospel to all nations" when, by their own theology, they ought to be writing "preaching the Gospel to all nations except, of course, the Jews".
Perhaps they will all have corrected, 'updated', their instincts by the time we get to the Pontificate of S Frances XII, goddess bless her.
*Trigger warning here about the imminence of unAmerican Irony.