That Orthodox statement was one of four such (IIRC) that came out after the Anglican Communion made some enquires amongst some of the various Orthodox jurisidictions, back in the 20s-30s. That one reads most favorably, but all were in a sense favorable. But, between the lines, Orthodox do not recognise ANY orders outside Orthodoxy as valid, RC included. The recognise them as potentially valid, with the validity supplied by conversion to Orthodoxy. For Orthodox, as for the RCC, there is one Church, and they are it.
Ratzinger’s statement doesn’t have to be infallible; it still must be affirmed by RCCs, sententia ad fidem pertinens, at least.
I’m familar with (and argee with) the argumenta presented at your 2nd site. It is a summary of much other discussion, as found in Hughes’ books, and many others (Dix, Lula, Cirlot, Lowndes, etc).
Believe me, I wish it were otherwise.
Now, does that mean that Anglican orders are invalid, and hence so are their sacraments? No. But it means that is what the RCC teaches.
GKC
Anglicanus Catholicus