Impossible is not currently available directly to consumers. They do not make a meatloaf - it is possible the grocery store bought the raw product and is selling their own meatloaf.
Beyond seems to be moving into that space, and Impossible is giving them the moment. Whether (or if) Impossible can recapture that market segment remains to be seen.
Possible but seems pretty unlikely. Also, I don't think they'd be allowed to use Impossible's trademark in that case.
I feel like the GP must be misremembering.
Edit: the meatloaf was served by the deli premade, it wasn't sold individually packaged.