There is no such thing as a "Church of Moscow". It is a disrespectfull, schismatic, apostate slander, also used by globalists and insidious subversives, and it should have no place on an (Orthodox) Christian forum.
Those who use that term also often support the so-called "Orthodox Church of Ukraine" and other apostate "churches", which only shows in whose interest they work.
Тhe Russian Orthodox Church is recognized as canonical, and in liturgical unity, by all the other canonical Orthodox Churches in the world, so if it is illegitimate, then so are they.
Also, the ROCOR and the Moscow Patriarchate reconciled on 17 May 2007; the ROCOR is now a self-governing part of the Russian Orthodox Church. So therefore, if the Moscow Patriarchate is not canonical, then neither is the ROCOR.
Without intention of defending Sergius Stragorodsky of a bad memory, episcopal legitimacy is not determined by one's political actions, but by the unbroken apostolic succession, which is not disputed nor in question here, and of which the author of this pamphlet seems to know little about, or deliberately omits.
It seems that this site is maintained by one person only, titled "Subdeacon Nektarios, M.A." and little if anything else.
His sole book is about the Greek Old Calendarists, a schismatic "church" of apostates, divided themselves into factions, whom he calls the "Genuine Orthodox Christians of Greece" and considers them the "Orthodox Church", and not apostates. Interesting.
As he says: "All of the material published by the Orthodox Traditionalist Publications does not represent the opinion of any local Orthodox Church or Synod", which means they may very well be heretical.
No reason for a canonical monk, priest, deacon or any honest Orthodox Christian to put up such a statement, so therefore we are dealing with either a subversive, hidden under a veneer of "traditionalism" (it wouldn't be the first time) or, more likely, with an overzealous and not-so-well-versed apostate-minded person, which is the other side of the problematic coin. Because if all canonical churches in existence (including the Mt. Athos) consider the Russian Orthodox Church canonical, how come the opinion of а some subdeacon has a higher priority? Makes one wonder.
The author should consider spending some time in a monastery before writing anything else, to learn some humility, gain some phronema and avoid falling into prelest. "Spiritual knowledge without praxis is the theology of the demons." -St. Maximus the Confessor