It's not distribution's fault. It's based on when the store orders. If they sit on say, the Hobgoblin wave forever, and then finally had enough peg space for a new case, they could have never gotten the Rhino wave and are now getting the Space Venom wave.
I can't confirm for all retailers, but based on when I ordered product for retail stores, you order a new SKU when it becomes available, and you have space for it. So the Abom/Space Venom/X-Men SKUs are very likely available at many retailers, but if it's not time to order a case, you won't see them yet.
Additionally, if you go to a store with say 10x Misty Knights, and she came one per case, that store ordered at least 10 cases since the wave came out. And people bought every figure but her. So you've had at least 10 opportunities to get the figure you wanted from that wave. The best thing you can do at that point is, buy a bunch of the Mistys, and resell them on eBay, maybe with the baf piece separate, so you break even. Then, ask the store when they'll order a new case. If they're nice, they'll do it for you on the spot and tell you when to expect it. You can even check to make sure they order a newer SKU so you don't see the old wave.
tldr; keep shit moving on shelves and you'll see new figures and waves. It's almost never Hasbro's fault. It's the collectors not buying the entire case so retailers can kee product rotating.