I would be surprised, but it's possible. While I'm amazed that Intel supported it as recently as 10th Gen, this would've been a very rare option. It would've also been limited to the bargain basement models, not a developer machine.

You'd have to go all the way back to 5th Gen (released in 2014) to find mainstream DDR3, and most of those couldn't do 16GB.

It's possible, just rather unlikely to have 16GB of DDR3 in a laptop.