I am not a fan of the feeling of being forced to pre-order something just to get some limited ingame item which you cannot get otherwise.
I mean, I would consider it fair if you can at least buy the missed pre-order boni as extra DLC.
Maybe this is not relevant much now, but I would welcome if anyone consider making a mod - even a simple skin port - from pre-order objects like Palico and Palamute skins available for everyone, even if it replaces a layered armour.
amiibo wise someone made Sinister set available already, thankfully. But Sunbreak is coming with amiibo stuff too, and I have little hope that they become available as DLC for PC.
Plainly, I am not sure if making limited items would be considered legal or not - but being locked out of content because of a different console or not being able to afford the game right away for pre-order feels wrong to me.