Currently you may or may not get an email, and it doesn't really matter. After a while (currently undetermined amount of time) and after you sign in, it will be in your Library ready to download (currently unpredictable download reliability).

Hopefully all the bugs will be worked out soon. Yamaha needs to let us know if the packs are compatible with our keyboard BEFORE downloading, instead of finding out the hard way AFTER downloading and trying to load into Expansion Manager. In fact they need to bring back the search by your arranger keyboard model, rather than lumping all packs together without knowing for sure it will be compatible. Guess they have a long way to go.