My understanding of how it's supposed to work is:
Once everything is up and running, you will be able to claim MYW tickets using
MDE and associate them with a MagicBand. You will also be able to claim MYW tickets for any Family & Friends profiles on your account that you manage using MDE and then associate those MYW tickets to that persons MagicBand. I believe there will also be a link to claim MagicBands. It appeared briefly on the MDE website, but was taken down just as quick.