That's your assumption, but all the evidence points to the opposite conclusion.  It's also incorrect to say that there is no bike facility along the road.  There are bike route signs along the road.

The Bike KC Master Plan (https://drive.google.com/file/d/1U9Bdz-xaNzXBN-MDH0QTlIR624cVlF33/view?pli=1) identifies these signs as "share the road signs" for "shared streets" (pg. 45).  The plan acknowledges that shared lane markings are often absent on such routes (pg. 67).  Maps in the master plan show Meyer as an "existing signed bike route/shared road route" (pg. 46), to be eventually upgraded to "major separation" bike path route (pg. 56).

Other sources confirm the MARC map. Jackson County Parks & Rec calls it a "on-street bike trail" on their map: https://www.makeyourdayhere.com/files/assets/parksrec/parks/documents/sw-county-trails.pdf

KC Parks & Rec show a picture of the roadway, not the sidewalks, on its "Meyer Boulevard Bikeway" page, and refers to the bikeway as a street trail: https://kcparks.org/places/meyer-boulevard-bikeway/

Planning documents for the proposed Meyer Boulevard road diet show the possible addition of bike lanes and shared bike-ped paths in the future.  Such changes would be unnecessary if a shared bike-ped path already existed along the corridor (https://www.kcmo.gov/home/showpublisheddocument/3493/637050051816400000).

All the official evidence confirms that this is a on-street bike route, as does the on-the-ground signage.  