SO I got a reply from Rare themselves, Unusual I know but i did.
No gifting options as such. You can gift on the MS store but you will need the other persons email address to do so. This is not cross region though. So like me, I was planning on a giveaway on my stream, that makes it very hard. You can't gift AC so that rules that out.
There's no gifting in game like most other games.
You can gift the plunder pass in Steam, if they use steam to launch the game.
Its very broken, and considering its size, and the fact we're on season 6 and all the events previous, this needs to be a thing by now.
So there's the Tea guys and gals. Gifting needs a degree! lol