On the Disney World Mom's question and answer thing on Disney World's own website it says they've rolled out a refillable bucket for annual passholders that is good for length of pass in Disney World. I can't find it again but it was from sometime in 2018 I think. It also says refillable for annual passholders is only for Disney World on another Mom's panel answer which I found looking for the first one I mentioned in this post. Then the Disney website touts a special refillable bucket for annual passholders at California's
Disneyland. So I'm going with as usual confusion reigns and YMMV.
My next door neighbor's workmate got a refillable bucket in early February in Disney World and passed it on to the neighbor for their trip in late March. They found the exact same buckets still on sale in some locations and had no trouble getting refills although I think they said they paid $1.79 for the refills. That may just be the approximate price with tax possibly. They've offered it to us for our trip.
I could pretend to be all goody two shoes but I won't. Other than the fact our trip is so far out I'm sure they won't still be selling these buckets, I'm of two minds about this. On the one hand I see that it technically circumvents the rules. On the other hand from the standpoint of Disney surely they expected some of this and have priced the popcorn only option so that they make money on it. Given I can buy a 12 oz bag of unpopped corn for less than the refill costs guessing this is correct.
I actually started looking into this because I was curious whether it would be allowed to get the refillable bucket I purchased when we visited Disney World in the early 2000's refilled. I paid $15.99 and there was nothing anywhere about how long it was good at the time. I will have to look for it but somewhere I have a picture of the sign I took at the time because we thought we'd be returning the next year. We talked to someone at our resort who'd bought one the year before and had no trouble refilling it back at that time.