I think the big reason we didn't see the actual combining Zords at retail was because of how expensive they were. It would cost $100 to get enough of them to make a Megazord, $160+ if you want the Ultrazord. Or parents could just get the dang Ultrazord for $40 even if it didn't combine.
The Lightning Collection figures, the smaller normal-sized Beast Morphers Ranger/enemy/Beast-Bot figures, the role-play morpher and weapon toys, and the simplistic non-combining megazord toys have all been very easy to find at various Targets and Walmarts. It's only been the actual combining Beast Morphers zord toys (which are bizarrely being sold individually this time) that have been hard to find in stores.
I don't know about Hasbro's general policy but I know everybody was on lockdown for Frozen II, which included both LEGO and Hasbro. Plus, I'm guessing everybody is holding off PR for NY Toy Fair? Overall, it's best to remember that Toy Fairs are for buyers, not fans.
In 50 years, retail will be dead because all stores are staffless fully automated operations controlled by Amazon. The UBI will be less than a fifth of what it actually costs to live after two decades of cuts and.a steadfast refusal to match inflation.