An important matter to observe which hasn’t been discussed thus far is if the goal was to “tamper” with the Denzinger, who would be stupid enough to omit the number of the proposition condemned instead of just editing the numbering system altogether as to give the illusion that it never existed in the first place?
Going from #729 to #731 is obviously going to raise some eyebrows.
No, Rahner as much as he was a modernist still had intellectual honesty such as can be seen by his other works where he affirms (as an exercise of the historian) EENS historically as the Church taught it, confirms V2 being a departure from previous magisterium, etc.