Latin was the standard language of the Roman-Catholic Mass until the Second Vatican Council in the 1960s. The current form of the Mass in national languages was formalized in 1970.
But does it really matter what the details were? The most important thing is that the standard published in 1963 was 7-bit. I mentioned that the 1963 version did not include lowercase letters. The (unpublished) 1965 version, mentioned on the first scan page, did.
As for the name, the acronym ASCII comes from the 1963 version (American Standard Code for Information Interchange). Later in 1966, ASA became USASI, and the official name was changed to USASCII, with ASCII as an acceptable alternative abbreviation. Later still, in 1969, USASI changed its name once again to ANSI, and an attempt was made to rename it ANSCII, but this did not catch on, and ASCII returned as the official name.
As for this 8-bit extension (not seven-bit code proposed by the ISO), perhaps they were referring to ECMA-35, the first version of which was published in December 1971? Or perhaps other proposals mentioned in the brief history. Of course, it seems that ASCII - regardless of the version - served as the basis for these extensions.
In general, I agree with your conclusions. However, I found it interesting that this document made no mention of ASCII or other 7-bit character sets. Especially since the first version of the standard (X3.4-1963, no lowercase) was already several years old at that point.
In this document [1] dated 1967-68, on page 8, IBM mention 8-bit character sets only: their EBCDIC and the "8-bit extension of the 7-bit code" proposed by ISO.
Because eight rather than six bits are used
to represent a. character, up to 256 possible characters
could be represented in the Extended Binary Coded
Decimal Interchange Code (EBCDIC) shown in Figure 7. Except for certain teleprocessing equipment,
the code that makes use of characters is either
EBCDIC or an eight-bit extension of a seven-bit code
proposed by the International Standards Organization.