Battery Swap Pilot Program Invitation

Last week I got an e-mail invitation to participate in the battery swap pilot program.
Anyone else get an invitation or has done the battery swap?
Wonder if your guaranteed to get your battery back on the return trip or do you end
up with someone elses battery?

I guess this battery swap is dead in the water. Elon said in the shareholders meeting today that only 4 takers have gotten the battery swap since the pilot started. So they sent out another batch of invites last week (I guess that's why I got one). He made it sound like it's gonna get scrapped.