I think the digital upgrades obly includes the greymoor chapter
Lois McMaster Bujold "A Civil Campaign"Reputation is what other people know about you. Honor is what you know about yourself. Guard your honor. Let your reputation fall where it will. And outlive the ***
if you buy a full copy of the game WITH graymoor and then redeem the key to your main account? you will keep all your characters, and the rest of the progress, while adding all the chapters without the need to subscribe to acess them and will have the classes that came with those chapters included in a purchase, instead of having to buy them separately from a crownstore. (I don't believe full game with Elsweyr still comes with previous chapters included, though I could be wrong. i know that full graymoor copy - does)
how do i know? physical collectors editions of expansions didn't used to come as upgrade. only as a full copy of the game + new expac.
but you MUST redeem the key to your existing account. do not create new ESO account. redeem the key to the same account you use to log into the game right now.