You can get premium movie channels & Locals - so I don't see why you can't get the supers. Call and ask - or better yet do an online chat. That way you can get it in writing from a CSR that it won't kick you out of Absolute HD.
Was able to add it online, it confirmed that Absolute was still my programming package after I ordered the Superstation pack. Oddly, it did not give me the choice at first...only the RSN pack.. added that then got an error that I needed one of the 'colored' packages! (lol) - went back and the Superstation pack was there, added it, confirmed that my package was Absolute + Superstations and everything is rosy again!