I don't get the point of this thread unless OP already clicked on the URL link from the email and was actually offered something.
We all know UA IT sucks. They clearly accidentally sent you the email since you haven't even traveled to LHR yet. If you click the link and enter your details it will likely come back to you and tell you, "Oops, sorry. You're not eligible for anything." If you do get an offer of sorts then take it and move on - but that's just UA's crappy IT.
-RM