When did they become human remains? Before or after launch?

Long before. Its a company that, after your death, will fly some of your ashes to space. For orbital services, the ashes are then returned to your estate, and in this case that can't happen because the vessel wasn't recovered. They also offer deep space launches where your ashes never come back.

The actor that played Scotty on the original Star Trek has his ashes flown to space, as an example.