One of the biggest problems with these long hiatuses is the fandom has limited information to work with for so long, and we build it up with speculation and theories, which become commonly accepted and built on further and things start to get tied together and consensus gets confused with canon.
People have generally accepted that Jarco is dead in the water since the Season 2 finale aired (seven months ago tomorrow, by the way) and we found out Jackie was notably excluded from the intro in April.
Jackie hate, whether as a tongue-in-cheek meme thing or in serious discussion about character depth and progression, has been such a recurring feature in these threads that people start projecting it on the show - and that's on top of the longstanding Starco/Jarco ship war that went hot almost a year ago.
The reality is that Star and Jackie haven't really directly interacted much at all, maybe in half a dozen episodes across all of last season and "Just Friends" was probably the first and last time they had a real conversation. Star was only ever hostile to Jackie in "Bon Bon" (and for one line in "Fetch" which is easily the funniest part of that episode) when she let her envy and jealousy get the better of her. When it caused her to unconsciously hurt Jackie (and Marco), she immediately felt shocked and ashamed of herself.
Star doesn't hate Jackie, wish to see her hurt, or want her relationship with Marco to fail, especially if it's because of her actions. If Jackie broke up with Marco due to the fallout of Star's confession, Star would never forgive herself. Star's game plan in Season 2b was to choke down her feelings until they go away and she could be happy for and with Marco again without it killing her inside.
That's how things stand now, but there's really nothing to do but wait and see how this mess sorts itself out when the new season starts.
That and wait for them to drop some "Smooch Buddies"-tier promo to twist the knife deeper.