No...

It means they have deducted the miles and are sending a paper cert. You may have been upgraded, if there was I availability then you can be confirmed on the spot. If you haven't, then you can continue to call UA and ask them to check LH upgrade avialability. If you don't clear before the day of, ask to be put on the list at the airport. Either way, you need to make sure that you give them the paper cert. If you end up stuck in Y, then you can return the cert for free re-deposit of the miles.