Concern for the new English translation example: Advent I

(This comes from a thread on Catholic Answers Forum about the new translation.)

The following prayer is an example of poor translation: a pronoun not connecting intuitively with its antecedent. This example is sadly one which we will hear on the first day of the new translation's use!

First Sunday of Advent - Post-Communion

May these mysteries, O Lord,
in which we have participated, profit us, we pray,
for even now, as we walk amid passing things,
you teach us by them to love the things of heaven
and hold fast to what endures.

What is the "them" referring to? It's so far away from "mysteries", and much closer to "passing things" (which it immediately follows) that the average reader -- or, more to the point, listener -- will connect "them" with "passing things".  So this prayer will be interpreted to mean that the Eucharist will enable the "passing things" of this world to teach us "to love the things of heaven."

That's not what the prayer really says!

Prosint nobis, quaesumus, Dómine,
frequentáta mystéria, quibus nos, inter praetereúntia ambulántes,
iam nunc instítuis amáre caeléstia et inhaerére mansúris.

In the Latin, there is no confusion: "quibus" (by which) is in the ablative, and immediately follows the ablative expression "frequentata mysteria". The phrase "praetereúntia ambulántes" is in the accusative, as required by the preposition "inter".

Here's a rough literal translation, with the word order as it is in the Latin:

May [they] be of benefit to us, we pray, Lord,
[these] frequented mysteries, by which us, while walking amid passing [things],
even now you teach to love heavenly things and cling to abiding [things].

The "by which us ... you teach" is rendered like that simply to match the Latin word order, but it is really "by which you teach us". Here's a cleaner translation:

O Lord, may these mysteries we frequent profit us, we pray,
for you teach us by them, even now as we walk amid that which passes away,
to love heavenly things and hold fast to that which endures.

The previous revision of this prayer, from 2008, was clearer than the 2010 version:

May these mysteries in which we have participated
profit us, we pray, O Lord,
for even now, as we journey through this passing world,
you teach us by them
to love the things of heaven
and hold fast to what will endure.

It was clear that "them" refers to the "mysteries", despite the distance between "mysteries" and "them", because there was no other plural noun to confuse "them" with. Sure, the plural expression "praetereúntia ambulántes" was made into a singular (but collective/encompassing) noun "this passing world", but that sort of adjustment is not forbidden, and it is done elsewhere even in the 2010 translation!

So this is not a matter of getting used to Latin syntax (not required by the translation guidelines) or some elevated language.  This is a bad editorial decision, a poor translation.