"This does not imply that the saints in heaven therefore must be omniscient, as God is, for it is only through God’s willing it that they can communicate with others in heaven or with us. And Boettner’s argument about petitions arriving in different languages is even further off the mark. Does anyone really think that in heaven the saints are restricted to the King’s English? After all, it is God himself who gives the gift of tongues and the interpretation of tongues. Surely those saints in Revelation understand the prayers they are shown to be offering to God."
The above is an appeal to what 'must be' if the necessary conclusion is to be reached. We still have no more 'evidence' that such is the case.
The point is that Heaven isn’t a “place”, restricted by the same temporal and physical constraints that exist here on Earth. Given this, we cannot compare the experiences of a person here on Earth, “plagued” with 1000’s of prayers at once, with the experience of a person in Heaven. To do so is, as the article says, appealing to a primitive (if not childish) view of Heaven.
This does not appeal to the question, this is a fact (people in Heaven are not restricted by temporal and physical constraints) that is apart from the original question (How can the Saints in Heaven answer 1000’s of prayers at once?).