I revisited the Amazon.com (US) link for the Ironhide & Prowl 2-pack. It no longer appears when using Amazon's search function, so I had to dig up the link when I had it saved. It now says "temporarily out of stock."
https://www.amazon.com/Transformers-...dp/B07ZPL7DXZ/
I don't know if that means Amazon ran out of stock while fulfilling pre-orders today (and got oversold), or if the item just got completely cut off like what's been happening with Amazon Canada.
And so far, I've still heard no updates at all on if Amazon Canada will ever bring in that Autobot Alliance pack, the Conehead Seekers pack, or the "dead" Optimus Prime.
ADDENDUM: I scoped out TFW2005's boards; looks like some of them did get the Ironhide & Prowl set, so Amazon probably just sold out.