SanzinDrop is known for doing that with USB listings as they know it's a selling point but to be fair this product came out about 3 years ago. Yea true USB-C has been out for a while but it's been slow to be adopted because of the extra price and engineering involved.
But yea if they don't list USB-C specifically, always assume micro because trust me if it were C then they'd want to point it out.