Buying Heavensward

So I'm not new, but I'm curious if anyone knows how this is going to work on PC. I bought the base game through Steam. I saw the Gamestop near me taking preorders already so I put $5 down.
I realized yesterday that that might be an issue. I'm not sure how that would work with installing a non-Steam expansion on top of a Steam base game. Does anybody know how that sort of thing will work, like if its just activating a product key with my SE account and downloading like any other patch?

I want to say be safe rather than sorry and see if Steam will launch a version.
I got burned when I bought GMG version thinking it was Steam and it wasn't.. Needed to redo whole trial as it was not refundable.

They ended up posting this on Twitter earlier, so that answers my question.

Quote:

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Originally Posted by @FF_XIV_EN

Steam users: If you've purchased FFXIV on Steam, then you must purchase the Heavensward expansion on Steam as well. http://sqex.to/6YX

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