Hello Adamos, I get your frustration. I have been signed up as well, but have yet to receive an email. In any case i'm sure you're aware of the requirements, but just in case.. You need to be running at least Windows 8.1 or higher (by which they could only mean W10), also you'll get the official link to download the app/update (not sure which it is) only when the languages you selected are available (I'm guessing that English might be the first one available; don't hold me to that though) and finally (and this is the killer xd) they also check if you had entered a registration code when you signed up. I'm guessing certain people received one and those will get this update/app first, especially since there were 50.000 people who signed up as soon as MS gave them a chance too and by now that total should be higher..
All in all, I wouldn't worry about the mail
It might've been just a mistake, but you'll get your chance, if you signed up and meet all the requirements