I can’t speak for VanMoof but the Bosch ebike motors definitely have a torque sensor (+), and my old Douze had one, too. You can’t do proportional assist without a torque sensor. I would consider it probable that VanMoof has one, too.
Nope, Van Moof uses a cheaper cadence sensor not a torque sensor. Bosch ebike motors are amazing and a huge step up, but bikes that use them generally sell for $5000+ and the Van Moof S3/X3 are half that price.
(+) some folks on a German forum reserve engineered the can bus protocol for the Bosch motor and it exposes torque https://www.pedelecforum.de/forum/index.php?threads/bosch-ac...