Ping!
"the bishops are fearful lest the generalization of the use of the Roman Missal of 1962 would relativize the directions of Vatican II"
The unity argument is of course hogwash, leaving the above as the explicit reason for their fears. They (and their 25 or so remaining regular Mass goers) are following the hermeneutic of rupture, instead of the hermeneutic of continuity. Or as one venerable prelate once said: "It is as if they think the Church only just began with Vatican II".
The prophecy that the motu proprio will cause "atomic warfare" in the Church is coming true even before its publication, I think. If you look, you can see how the sides are lining up, in the episcopates and so they say, in the Curia.
When I think about this my Agent Orange starts acting up.