I can’t seem to understand how it is that the Vatican at that time thought that removing, even going as far as prohibiting,
When Sacrosanctum Concilium was voted on during Vatican-II, 2,147 bishops voted in favor of it and 4 voted against it. SC was not intended as a specific outline of exactly what changes the bishops wanted; but by that time all know that liturgical research had been going on for better than 60 years, and they wanted to make changes to the Mass.
We need to remember that the Council of Trent also made changes; and subsequent to Trent, changes were made periodically. It is also clear from the language of SC that it was more than just a minor tweak here, a minor tweak there; and the arguments over how much change the bishops wanted has continued since the OF was promulgated.
I suspect that if you were to go back and ask those bishops (most all of whom are deceased), none of them had any thought that we would have an EF and an OF; they presumed there would be changes, and just as in the past, once the changes were made, they were implemented everywhere; and so it would be again.
I don’t intend to get into “the bishops did not intend so many changes” as those bishops are dead and we cannot ask them.
Rather, the OF was promulgated, and some - particularly those who felt that the Mass needed no changes whatsoever, and others who felt that maybe a minor tweak here and there was all that was necessary - came out loud and strong during Pope John Paul’s reign, and he eventually allowed a limited usage of the EF (not called that yet). Part of the issue was the SSPX, which went back to Pope Paul’s reign and John Paul “inherited”.
When it came time for Pope Benedict, he was still dealing with the SSPX and others who might not be going to an SSPX chapel, but were vocally supportive of their position(s). He said that the EF had never been officially abrogated; but then, I am not sure that changes from Trent forward ever were accompanied by an official abrogation; someone may want to research that.
So the short of it was that I don’t think the bishops at Vatican 2 could foresee the reaction to the OF - which was not yet promulgated; nor do I think they particularly were concerned with an official abrogation; The Mass we had would be modified and all would move forward with it.