What is a 73W aircraft
According to https://www.airliners.net/forum/viewtopic.php?t=241063 (and others) B73W is a newer version of Boeing 737-700. A one with winglets installed.
So, it's not B737 MAX 8.

A more comprehensive list (which sadly does not include 73W) is here What is the difference between Boeing 73G, 73H and 737?.