Fwiw, here are the arguments in favor of this reading (yes, there may be pushbacks to this reading, too):
1 An argument can be made that it is better to translate Judges 11:31 as “it shall be that whatever comes out of the doors of my house to meet me….it shall be the Lord’s, OR I will offer it up as a burnt offering”, rather than “…AND I will offer it up as a burnt offering”. That is, there’s an either/or aspect to J’s vow.
2 That is, the sense of 11:31 is that J recognized that whatever might greet him at the door might not be legit to sacrifice (ie, like a human! – cf Lev 18:21, 20:2-5, et al), and if it wasn’t legit to sacrifice, J would dedicate it to the Lord (“it shall be the Lord’s”). Perhaps like Hannah dedicating Samuel (1 Sam 1:11)
3 J’s commendation in Heb 11:32 ranks Jephthah as part of the faithful (so the theory would be if J had really sacrificed his daughter, he wouldn’t be commended).
4 The priests and the Israelite people would have prevented Jephthah from carrying out his vow if it meant the sacrifice of his daughter. This is particularly definitive given the time lapse between the vow and its fulfillment.