If you want to find out exactly what Westjet has planned for the 737-200s in it's fleet regarding how long those jets will be around with the airline, the best forum to ask in is the Civil Aviation Forum. The guys in there know the airline industry inside & out! You might even get actual dates & schedules about the remaining service of Westjet's 737-2's from those guys .... I wouldn't be surprised!
I'm not trying to suggest the members of this forum couldn't answer your questions of course (90% of my posts on A.net have been in this forum over the years, although I've been doing mostly reading than asking questions lately).
It's just a suggestion for you to help you get some good info.
, I haven't flown with Westjet "YET
!", but my wife Phyllis (aka Vaporlock in the forums) did last May and really enjoyed their service. Here's a shot she took of the 737-7's cockpit overhead panel ... that she flew to YVR
View Large View Medium
Photo © Phyllis Purich