Keeya, it matters to you in that the ETF doesn't get the phone unlocked. You mentioned the contract status of the phone. I pointed out you were incorrect in making that claim, and you remain so.
You'll be hard pressed to find a free one. From what I've seen, unlocking the Sprint version is usually a bit more costly than unlocking the AT&T phone. You might end up being better off selling that particular phone and buying either the AT&T phone or a Verizon version if you were looking for the CDMA version.
As for the site you linked, it doesn't load when I try and I've never used it.