The question is still of no interest and it has nothing to do with the consequences of the argument. It is not possible for the “received and approved” immemorial Roman rite to be reduced to the status of an Indult or grant of legal privilege regardless of the conditions. It becomes even more unpalatable when the conditions are morally and doctrinally repugnant.
What I think you're saying is that you think the 1949 missal is the "received and approved" rite, so any attempt to give it as an indult would be void. If so, how is that different than Pax's argument about the 1962 missal - that
1962 is "received and approved" and the later attempt to give it as an indult is void? The 1962 missal, like the missals before, included Quo Primum and the constitutions of Urban VIII and Clement VIII; it is prima facie in the line of revisions of the missal of St. Pius V. This is unlike the missal of Paul VI which only has the constitution of Paul VI - it clearly started a new line.
However, if you're saying that 1949 has the capacity to be "received and approved"
because as far as you know it hasn't been given as an indult, that is a question of fact. Indults have been given for things other than 1962. I recalled one for a church to use 1949, but unfortunately can't find verification any more, so something may have changed,
Nevertheless, as you must know, the FSSP has an indult to use the old holy week (from before 1952). According to the way you apply your argument to 1962,
because the old holy week has been given as an indult, and an indult is not compatible with the received and approved rite, the old holy week cannot be the received and approved rite.
I could see someone object that this FSSP indult is for only the FSSP, and it has one prayer different (and I'm sure you can guess which one if you didn't already know). If so, then consider that the SSPX (and probably many other priests using 1962 missals) do some details different, too