Apparently, no, they cannot merge a new EA account with my existing EA account because I have linked my existing EA account with Steam.

Time to head to help.ea.com - I have a lengthy discussion with someone on the chat. So maybe I think I'll create a new EA account and link this with my current Xbox Game Pass account and then have that merged to my current EA Account - the one with all my content. So I think this is a bit odd, I know I can't merge my Xbox accounts, the old one with the new, I've been down this road with Microsoft before. No dice, I know see a message that says I can't link my EA account with my current Xbox account because it has previously linked to another Xbox account in the past. I don't ever recall linking this to my EA account, but no big deal, or so I thought, I'll unlink this old Xbox account that I don't use and link it to my current Xbox Game Pass for PC account that I use and pay a subscription for when I log back in. I have to think about this as I don't recognise it, then I recall this is an old, old, Xbox account from when I had an Xbox 360. Go to sign in and it tells me that my EA account is already linked to a different Xbox Account. Fine I guess, another launcher, but hopefully it will play nice with GOG Galaxy 2.0. The EA play content comes up on my Xbox Game pass for PC as being available, that's great! Looks like I have to install a Beta of EA Desktop which appears to be replacing Origin.

I also have an Xbox Game Pass for PC subscription and have been eagerly awaiting access to the EA Play library since it was announced last year. I have a reasonable amount of paid content on it, 20+ titles. I have an EA account, have had so for years.

Connect xbox game pass to ea play