How are sheet pans a new thing? I’ve had mine for decades, so long I can’t remember when or where I got them. Did you really have to buy them at a restaurant supply store or a specialty shop like Williams-Sonoma? I’d had them for a long time when I got my first Silpat, which was so long ago I can’t remember where or when I got that, either.
The Times likes to “discover” things that pretty much the entire world already knows about. Here’s Brian Williams mocking their “discovery” of Brooklyn (starts at :16)
A friend remembers buying a pack of heavy-duty half sheet pans at Price Club, so likely I bought ours there, circa 1990, a decade before Nordic Ware started trying to sell them retail.