Do physical releases count as Lost Media?

Sure in theory it could, especially for stuff that's REALLY rare and long out of print like the Golden Book VHS releases of Kidd Video. Most of them are virtually impossible to find now(and some listed releases like Euphonius the Melodious Dragon we're not even sure if they actually exist or not)

There's also stuff that was going to come out on DVD but got cancelled at the last minute like season 3 of Adventures of Pete and Pete. It was supposed to come out on February, 28th 2006 but got pulled from the schedule shortly after Paramount bought out Dreamworks and merged with them. According to a 2014 L.A. Times interview with the creators of Pete and Pete those season 3 DVDs were already pressed and are just sitting in a warehouse somewhere, not sure if that's still the case or not but it's entirely possible. I actually took it upon myself to send Paramount Home Entertainment a message on their Facebook page asking them about this today, hopefully i'll get some kind of response, who knows maybe they'll recognize the opportunity to make quick buck and the DVDs up for sale?