Incredulous recently posted a video of a Condit/Matatics debate, and DecemRationis recommended a section of a few minutes thereof, where Matatics mentioned Is 22:20-25 as relevant for the situation today. I think that's pertinent to the question about the indefectibility of the Church. Here the verses:
[20] And it shall come to pass in that day, that I will call my servant Eliacim the son of Helcias, [21] And I will clothe him with thy robe, and will strengthen him with thy girdle, and will give thy power into his hand: and he shall be as a father to the inhabitants of Jerusalem, and to the house of Juda. [22] And I will lay the key of the house of David upon his shoulder: and he shall open, and none shall shut: and he shall shut, and none shall open. [23] And I will fasten him as a peg in a sure place, and he shall be for a throne of glory to the house of his father. [24] And they shall hang upon him all the glory of his father's house, divers kinds of vessels, every little vessel, from the vessels of cups even to every instrument of music. [25] In that day, saith the Lord of hosts, shall the peg be removed, that was fastened in the sure place: and it shall be broken and shall fall: and that which hung thereon, shall perish, because the Lord hath spoken it.
This obviously refers to the Pope, allegorically, as can be seen from verse 22: "And I will lay the key of the house of David upon his shoulder: and he shall open, and none shall shut: and he shall shut, and none shall open." The Pope, or rather the office of the Popes (throne of glory) is compared to a peg (tent-nail), fixed in a sure place, ensuring that the Tabernacle (tent) will stand and endure even hot winds from the east without being flattened.
In the last verse, that peg is removed by the Lord, and all that hung thereon, shall perish. That's "in that day" (of the Lord). That's in the time of Antichrist. So there won't be Popes during that time. It's not the gates of hell prevailing over the Church, it's the Lord pulling the peg.
That's not my interpretation. See Father of the Church
St. Jerome of Stridon, patron of Scripture studies, as well as French Benedictine monk
Venerable Hervé de Bourg-Dieu (12th century), who is particularly known for his Commentary on Isaiah:
St. Jerome on the last verse of Isaiah 22:
[...] Quod sequitur, videtur sensui nostro esse contrarium, quomodo paxillus iste, qui fixus fuerat in loco fideli, auferatur et frangatur: et cadat et pereat quod pependerat in eo, et hoc fiat quia Dominus locutus est. Quod ita solvi potest si legamus illud Evangelii, quod in novissimis diebus refrigescat charitas multorum (Matth. XXIV); et ipse Dominus dicat: Putas filius hominis veniens inveniet fidem super terram (Luc. XVIII, 8)? Non ergo paxillus frangetur et cadet et peribit, quod impium est dicere: sed paxillus auferetur de loco fideli, hoc est, de Ecclesia per impietatem quotidie subcrescentem [...]
Corpus Corporum[...] What follows, will be seen contrary by our senses, in what manner this peg, which had been fixed at the sure place, will be taken away and broken: and which hung on the peg fell and perished, and this happens because the Lord has spoken. What can be resolved if we read the Gospel, that in the very last days the charity of many shall grow cold (Mt 24:12); and the Lord himself says: But yet the Son of man, when he cometh, shall he find, think you, faith on earth (Lk 18:8)? Hence, the peg will not be broken and fall and perish, to say that would be impious, rather the peg will be taken away from the sure place, that is from the Church by the growing daily impiety [...]
In the very last days, the peg will not be
broken and fall and perish, rather it will be
be taken away,
because the Lord has spoken, because of the the growing daily impiety of Catholics.
Venerable Hervé de Bourg-Dieu makes it even more clear:
[Is 22:23] "Et figam," inquit, "illum paxillum in loco fideli," quia ipse continet Ecclesiam suam, et firmat, ne portae inferi praevaleant adversus eam.
[...]
[Is 22:25] "In die illo," id est in tempore Antichristi, "auferetur paxillus, qui fixus fuerat in loco fideli, et frangetur," quia multi rectores de Ecclesia tollentur, et adversitatibus frangentur ac deiicientur, "et" fracto paxillo, id est iusto pastore "cadet" a fide populus, qui "perpenderat in eo, et peribit." Ut autem haec omnia inevitabiliter sic ventura fore monstraret, in fine subiunxit: « Quia Dominus locutus. »
Corpus Corporum[Is 22:23] "And I will fasten," He says, "him as a peg in a sure place," because He himself secures His Church, and supports her, that the gates of hell don't prevail against her.
[...]
[Is 22:25] "In that day," that is in the time of Antichrist, "shall the peg be removed, that was fastened in the sure place: and it shall be broken," because many leaders of the Church will be removed and broken and brought down by adversities. "And" the peg broken, i.e. the people "shall fall" from the faith, owing to the just shepherd, "which [faith] hung thereon [the shepherd], and shall perish." But to show that all these things will inevitably happen in the future, he added at the end: "because the Lord hath spoken it."
I think this ends all debate about Indefectibility of the Church in the current situation, if one realizes that we indeed, live
in the time of Antichrist.