All Expansions will be provided Free., however Micro-Transactions (well we'll see how "Micro" they are) for select Non-Essential Cosmetics... such-as Pets.
(at present a Cat and Monkey have been confirmed)
As it stands, Expansions are intended to release every 3 Months with new Cosmetics, Features, etc. with Weekly Updates that provide Fixes, Minor Content Updates, etc. provided on an on-going basis.
Sea of Thieves will almost certainly end up as a Permanent ("Killer App") for Game Pass.
This would make a lot of sense, as this provides Consumers with the choice between a Subscription or Retail.
Now a lot of this actually factors in with Microsoft' shift from "Generational" to "Tier Iterations" … it's a concept that was knocked around during the Xbox 360 Era, but under previous Microsoft Management just was never going to happen.
The idea is somewhat simple., basically to echo the PC Market., where you have 3 Tiers of "Gaming" Computer.
Low / Medium / High... or more specifically Minimum, Recommended and Ultimate.
At present this is the Xbox One, Xbox One S and Xbox One X.
I'm not sure how they're going to be handling the naming convention., but it would make sense if they break them down "Generationally" … so say:
Xbox 2-Series (Xbox Two [2020], Xbox Two S [2022] and Xbox Two X [2024]).
This would make the most sense., with each Generation giving them the chance to swap out the Internal Hardware... but within said Generation they all use the same Hardware just more powerful versions.
We can almost guarantee at this point they'll be using AMD Ryzen, Navi and HBM Hardware along with Windows (10) Core,. due out in 2019; but is effectively just Windows 10 without any Win32 Support.
This might not make sense, but remember it's easier to say "Supports Console X, Y, Z" as opposed to "Well it should run on Hardware X, Y, Z or Equivalent" when this isn't always the case.
So Console Gaming is just far less headaches, confusion and difficulty... something that doesn't even come at a Premium., typically unless your building a Custom Rig (and heck even if you are right now) … you can't Match a Console in Performance, Capabilities and Price.
ONE of those always has to be sacrificed, and with OEM (Pre-Built) Gaming PCs that's ALWAYS Price.
Consoles will always have a place., even if it ultimately becomes a Branded PC (akin to Amiga / Atari back in the day) because of their Plug-and-Play Nature and focus on User Experience as opposed to Technical Prowess.
If Microsoft actually follow through with this, or it just becomes a curious experience of the 2010s … who knows; but personally I'm looking forward to such an idea being allowed to blossom., along with Games like Sea of Thieves being Showcase Pieces that Evolve along with the Consoles and their Gamers.