Minnie's in-park character always has a fire Halloween costume every year that i wouldn't mind seeing any of them recreated for the players to wear, and of course mickey has a matching one for those that want to wear/prefer his or mix match, however you like.
There's lots of "simpler" tee's that could be recreated too for those who want to wear something less "costumey" like the mickey shaped bat tee/spider web tee, "trick or treat" shirts, villains tees (for example a black and purple top to mimic ursula's outfit with the necklace at the top by the collar of the tee so it's almost like a bounding outfit type thing). Disney's merch over the past year or so have been on the top of their game with stuff like that for everyday/casual wear but would work as halloween releases or used all year around too. Hocus pocus tees/jerseys, purple haunted mansion printed or leota head printed hoodie or even shirt, purple backwards flip with glowing blue leota, jack skellington white flip, candy corn leggings (similar to the candy cane ones), black shorts with mickey pumpkin on the front on one side or on butt or black leggings with green bats, hm leggings, etc or different color combo than the ones i mentioned.
As far as other hats go, taking the christmas/valentine's minnie ears and recoloring them to match the orange/black bow polka dot halloween park ones would be cool too or Sora's pumpkin hat patch from kingdom hearts. Any of the kingdom hearts halloween characters like Sora, mummy donald and spooky goofy could even be created similarly to the it's a small world dolls for room decorating. I've seen a mickey mummy and NBC mickey hat ornaments that would look really cool as ears as well, especially the mickey mummy. There's lots of ear ornaments that could be created into hats that are more intricate in a similar style to the winnie the pooh ones this month, for villains or princesses, or nbc, etc but i know those would take a lot of work. I don't know if it would be possible but the refillable popcorn buckets that the parks make, like the mickey pumpkin or the oogie boogie one from last year that I think DCA is getting this year? could be used as "hats" if the misc tab isn't being implemented yet so they look like they are hanging off their shoulder to "carry around". If the misc tab could be used, then the trick or treat bags and such someone else suggested would be really cool to add to that same idea. If not, the popcorn "buckets" would look cool as furni as well as a newer version of OG ones we got couple years ago.
I would say though that few years ago, when we got the changeable pillars and the purple bubbling plants that I'm forgetting the name of rn, ursula locket & maleficents staff, etc was probably my favorite month/year for halloween releases in general. Not just because the items were well designed but it gave the players a lot of small little furni that would bring their halloween themed or non halloween rooms together for building. I love plants, walls, panels, etc for building but small stuff like that really brings the aimed theme for the room design together. I would love to see more stuff like that. We've been seeing more of that over the past year or so in releases and some have even been animated and I'd love to see more of that especially since some more "halloween type" stuff is hard to pull off throughout other months in the year. I'm not sure if that makes sense, I hope it does lol
That year we also had the pumpkin candy crates that were really cute leaving them unopened filled with candy or opened where they were empty. They were really cute for decorating so if a crate system is not on the table as an idea (where even the simpler tees mentioned above could be used in as rewards) then something similar would be cute for decorating as well aside from the popcorn buckets mentioned so that we have something else to use besides the past candy cauldrons and candy bags.
A zero pet someone mentioned earlier would be really cute too, especially if he looks like a little baby zero similar to how ya'll did kevin's base pet couple months ago.
I really love halloween and there's so much potential for some really awesome releases than just rereleasing pumpkins/mickey ghosts that have been rereleased couple times already.
Like please actually take all my money with some really cool stuff because i'll definitely buy more excessively
I can provide some reference pictures if need be since i did base a lot of stuff off of some real disney merch