I remember, personally was not a big fan of the theory, but remember agreeing that there were strange coincidences with her clothes and other stuff.
What I never knew was if that thing some anon speculated about Daron saying that Jackie and 'others' being more than most of the public expect was true or not.
I can believe it, based on the fact that almost every character had something going on but was forgotten to do shitty drama, thing is I'd like to have some source on it.
We needed more Jackie in the show that would have cemented the death of starco, why else would they want to delete the only thing that united Marco and Star if it was not to make other ships possible?
Instead of Marco going to stay in Mewni it would have been cool if he brought his love Jackie and some friends to Mewni on every other episode to have some adventures.
Also. Fuck Nefcy, Bisignano and Cotugno for not giving us Neverzone Jackie.