Here are toys we do not yet have sightings of in the US (to the best of my knowledge):
Transformers The Last Knight
Legion Hound
Legion Dragonstorm
Allspark Starter Sqweeks
Allspark Megatron
These toys were all available on Entertainment Earth but only to be purchased with the entire wave which consisted of several repacks in every case. It may also be that Allspark Megatron did see a limited release on Amazon.
Deluxe Cogman was never found at US retail either though the entire wave was available for purchase at online collector oriented stores and online wholesalers.
Both Legion and Deluxe Hot Rod have never been found in Walmart stores but were plentiful online, making it a defacto online exclusive.
Robots in Disguise
Legion Cyclonus
Legion Heatseeker
These were not even offered in the US at the wholesaler level.
So if these are toys you saw in the US at retail, do let us know. And on e-bay ther is only 1 listing for Cyclonus, from Australia.
What is odd about all of these is that this is country specific. As you can see below, several of these toys were found at brick and mortar retail in other countries, just not the US.