Possibly, but there's no guarantee that they're interested in first-run rights for the specials, or that the BBC will want to sell them to someone who's going to sit on them when BBC America wouldn't. Sci Fi doesn't have the kind of prestige and clout NBC does, so the Merlin comparison isn't all that relevant.
SciFi has a ton more prestige than BBCA...
Does it? I thought the only "advantage" it might have, in terms of being connected to something relevant, is that SciFi is owned by NBC (just like they own BRAVO).
I'd think SciFi's real advantage over BBCA is coverage. SciFi is available on standard cable and is in almost every home in the US that has cable TV. BBCA is a digital cable and satellite channel, so while many homes do have it, I don't think it's as many as have SciFi.
So, if level of coverage impacts how one defines prestige, it might be considered more prestigious to air on SciFi. On SciFi, it has more opportunity to be seen, at least.