The name of the track subdivison is incorrect. Metrolinx refers to this line as the "GO Subdivion" on official planning docs, not the Lakeshore East Subdivision.

This document from Metrolinx refers it that way multiple times 
https://assets.metrolinx.com/image/upload/v1663237565/Documents/Metrolinx/2020-04-29-Bowmanville-Rail-Service-Extension-PDBC-Final-v3-1.pdf
Page 46: "Trains to successfully incline from the GO Subdivision at Oshawa GO
station to climb and connect into the GM Spur"