I don't assume that. I actually suspect they've been rolling along happily in the relatively carefree years without examining what they deeply want out of life. I said on page one the original post gave me 3 areas of concern, ultimately not really being about the wedding itself. If OP's DD can honestly say she's considered the deeper implications behind each of the "petty" wedding issues and is on the same page with her groom, so be it. If not, I'd definitely put a hold on wedding planning.
If the bride is not happy to make those wedding compromises, expresses them to the groom, he says he'd like the things he likes but is willing to compromise, then there's potential for them to work towards a future. It may well be the groom hasn't given some of his ideas serious consideration beyond the end of his nose because he hasn't had to yet. Telling your kids you will underwrite their wedding or assist with expenses isn't a blank check, not speaking financially but in terms of putting on a wedding that allows a true celebration.