gavra: Aside from the hashkafic/social issues others have cited, it is a halachic problem with the prenup itself (rendering a future Get Me’usa due to the pressure of a kenas on top of the halachic invalidity of the prenup itself since at the time of signing he expected it to never come into force) in addition to what I mentioned above. See the original thread (linked in the OP) that spurned this discussion as well as Rav Elyashev’s cited teshuva there.
If he really believes that there is still a chance at keeping it alive (and Bais Din agrees)
S”A doesn’t normally give B”D the ability to disagree with his request. It is rules and evidence based as defined in the S”A. If he is asking for shalom bayis and she is asking for a Get, even if she is claiming ma’os alei S”A rules he cannot be made to give up his marriage. Even if b”d is of the opinion they’ll never get along too well. S”A specifies only in extreme cases (i.e. proven abuse, physical deformity, etc.) can a Get be demanded of him despite his unwillingness.