They already screen test contestants around the country, so it wouldn't difficult to find a family or two with a serviceman serving overseas, stick 'em behind the Big Doors at the right moment, and have them model a car. If Ellen can pull it off, so can Price.
The man who gave Bob Barker his big break used to do surprise reunions all the time. I'd say Price isn't Ellen, Ellen can straight up rig who she wants to call up for whatever at her show because whatever game they're going to play isn't important and only serves as a framing device. Price is a game show. I think the idea of maybe choosing a family or two and springing a surprise on them either if they made it on stage or, if they didn't, before SCSD2 could be plausible though.
That said, I agree that, more than likely, by "Family Reunion" they mean they'll have two or more generations represented in pairs, trios or more.
Went to the first taping of Season 47 a couple of weeks ago (as well as the 3rd and 5th) and it was pretty fun. Standard shows, but each one has a little surprise that I and my friends weren't expecting. I'd say the only real changes to the show are that the square in back of the center audience section has changed to blue with a yellow border around a dollar sign and a new pull apart for the IUFB reveal. It looks like a cut out of the hexagons on homebase with three layers of colors (yellow, green and blue?) surrounding a dollar sign.