I agree with you, Corvis. The only way it is Stacey is if they have deliberately obfuscated her danger in order to hide the boot. I think though that they have America expecting Brandon to go, and that is the misdirection.I said essentially the same thing yesterday on the editing topic about how Mikayla's position is not being shown from her POV, and that she will lose the battle with Brandon. I also said there that this tension will fracture the tribe and it has to be addressed. It's a boil that requires immediate lancing or the infection will spread.
If Brandon were weak, he might be offed, but he is strong and it is only Ep 4, plus Coach indicated in Insider that Christine, Stacey, and Mikayla were all disposable to him back in Ep 3. Christine was just his biggest target. He will not fight for Mikayla, and she was a little slow in the wakeboard challenge. At least she was on the course when Jeff yelled that Upolu needed to pick it up.
I also compared Mikayla to Kelly B. Even though she is young and athletic, she just ended up on the social outs. Perhaps because she is young and athletic, she is the type who could damage her tribe by flipping at the merge ... has to be taken out.
It looks like Sophie and Albert are going to sympathize with her and not Brandon, from the preview. We already know that Sophie thinks Brandon is weird and creepy. So again if Coach wants to keep his chosen ones tight, he must get Mikayla out. Upolu could easily fracture into Sophie-Albert-Mikayla-Stacey (by default) vs. Coach-Brandon- Rick-Edna.
Hopefully, from Coach's POV, Albert knows better than to cement himself to keeping three weaker players this early in the game.
I could see Sophie straying from the fold or being taken out sooner rather than later if she pushes for Mikayla to stay.