Our family’s operational principles went like this: kids and parents got on the same page about the “apply to list”. Any conditions, any “if . . . then” statements that might depend on how future events broke, we tried to articulate before applications were finalized. The kid did a lot on their own to gain the credentials upon which s/he would be judged by the schools, including taking the SSAT. S/he did the daily tasks that created a multi-year transcript that would be judged, and did the ECs. Parents supported, but the kid was going to earn her/his own admit. The kid would be doing the living at the school and be expected to make it work to the best of their ability.
We parents felt that having vetted the list, it was important to put the final decision in the kid’s hands. Yes, the tuition was “gifted” to the student, but the opportunity was earned. If our kid had gotten into school X and we had then vetoed that option post-M10, without invoking our conditions or other compelling reasons, I think our kid would have been upset, given this approach to the process.
Regarding the OP, I would hope that there has been transparency and communication all along. If there were no circumstances under which the parents could see sending their child to St. Paul’s, then I don’t understand why they would have allowed that particular application to go ahead. I wish this family all the best in getting a quick resolution to the question of whether SPS is in fact a viable option if M10 opens that door. And, of course, all the best for the discussions that any other M10 school decisions may bring forth.