Am I understanding correctly that the trick-or-treat promo is next?

Yes that's correct

Then after the Trick-or-treat is the Celtic cards promo

So, um... I'm still a tad confused about the pass changes... (I have gone through the last, at least, ten pages trying to figure it out exactly, but I want to make sure I've got it correct)... If I'm reading it correctly... they're changing it to so we have the possibility to earn a pass every three days...? Will we have a new limit to how many passes we can obtain in a month? What exactly is happening?

I dont think the Bewithed pumpkin is coming out. Someone posted a picture a while ago of the prizes and there wasnt any Bewitched pumpkin there

And the Bewitched Pumpkin WILL be offered as a prize

We had a poll what do we think about the new change
"Its great! 31% 794 votes"
"I'm afraid of it 16% 424"
"I hate it 31% 811"
"First i have to try it 22% 562"
Like its so positive! Doesnt matter that more people hate the change. Almost half of us do like it !

is greyfell back in the cards? And do the joker cards for bronze, silver, gold and diamond cards exhist still?

How can people think it's "great" to go from being able to get 30 free passes per month down to 10? That's nonsense. This will also destroy the entire economy of value of horses in relation to age.

So... Pass horses will end FOR EVERYONE, not just for Czech server. This is answer from suppport (not mine photo, so I blacked the nickname) - translate is:
„The change will be added to the game. We announced it only to get to know reactions of players and to have a chance to modify the change.“
There it continues: „You understood wrong. We choosed only few versions for testing, but the change will be introduced to ALL VERSIONS of Howrse.“

I personally really detest the mini games, I never do them whenever they are placed in a promo as they are just a nuisance and a time waster and incredibly annoying. I also often forget to check the amount of points I have for the monthly pass as well because I so rarely seem to get the full 10 points a day and have no idea why so gave up.
So this whole change to the pass system to me is just pointless and stupid, as the criteria they expect me to meet is apparently ridiculous. I kill pass horses as and when I need them, no other time. So not overly impressed by this as it means you can't control when you get the passes, you HAVE to get them slowly over the month (if you manage to get all 10) instead of all at once as and when you want and need them. It's ridiculous

"Its great! 31% 799 votes"
"I'm afraid of it 16% 427"
"I hate it 31% 854"
"First i have to try it 22% 571"
We also made a petition, but to get at least a small chance... We would need way more signs. (We have around 160 signs)

Being that many players, including myself, are not lucky enough to get those 20 extra passes, I can see why most players aren't really bothered by the change. It's not a huge surprise to me.

Quite honestly, I'm excited for it. I might finally be able to keep my PA active since I won't have to spend so much time in taking care of pass horses. I can do what I normally do in a day and still get those passes.

I've been away for a while and got back about 1 day before the wandering horses arrived, will there be another GC/Lottery after the Trick or Treat promotion? Or does it only occur after 2 or 3 promos?