That's not uncommon in any shared universe, and why it's incredibly important for creators to work together and communicate with each other rather than play games with their rivals over characters who don't belong to them. And that goes for Hickman as much as Slott. Neither of which do anything without approval for their editors, even Hickman has a boss to answer to in Marvel.
But let's say you're right, why isn't Hickman getting blamed for something when Slott supposedly made the bait? That suggests Slott wouldn't have done anything without Hickman doing that but with these conversations Hickman's not getting any blame when he's the one who put Franklin in that position. He was ok with the recent FF/X-men mini-series, for example.
These two were at a creative summit and should be able to contact each other to hash out their plans and solve any disagreements between themselves, this theory alleges that they're not acting professionally and that Hickman succeeded in setting Slott up. Because? It can't be about hating the FF, he loves those characters and wrote them in their own title and Secret Wars. All this revelation, if it's true, and I haven't seen a shred of evidence that it is, just makes them both look bad - especially Hickman.