Is this the exact loop path or at least close to it per what the province released?
No. It hits all the key nodes the province is talking about and adds Markham Centre. This routing is more of a traditional urban metro routing where intermediate stops between key nodes are put in walkable locations directly next to transit oriented developments. Stops for The East Mall, The West Mall, International Centre / Malton GO, many hotels along the route, puts the town centre of Woodbridge within a walkable distance, walkable distance to all the density on Highway 7, Promenade Mall, the offices around Commerce Valley / Beaver Creek, McNabb and Warden, Victoria Park and Steeles, York Mills and Lesmill, and serves two Seneca College campuses. The goal of an urban metro is to try and make more trips possible without connecting to buses or walking a distance that would be burdensome or inconvenient, especially in inclement weather.
The provincial dotted lines completely follow 427 and 407 from Dundas in the east to Leslie in the west. It overlaps with the 407 transitway route from 427 to Leslie and I'm not sure how an Ontario Line using rail could co-exist with a busway that runs Burlington -> Mississauga Centre -> Pearson -> Vaughan Centre -> Richmond Hill Centre -> Markham Centre -> Oshawa route. Based on that I would guess the idea is to convert the 403-407-412 busway to a rail based operation. Being completely in the freeway ROW this East-West Cross-Regional Connection would be fairly affordable to build (no tunneling and limited expropriation) and still has the benefit of connecting Aldershot GO, Mississauga Centre, Pearson, Highway 407 station (Vaughan Centre), Bridge Station (Richmond Hill Centre), Unionville GO (Markham Centre), Locust Hill (mentioned by name in the plan so I'm guessing with a GO or VIA HFR station), Whitby GO, and Oshawa GO. Such a route is more suited to be regional rail than urban metro because it is longer distance and not focused on supporting local density. While urban metro and RER type services are both rail transit, the goals and therefore proper station locations and station spacing should be different. I'm not saying they shouldn't build this RER line, but an Ontario Line built as an urban metro replaces the Highway 7 BRT, whereas a 407 RER does not. Ontario Line technology and frequency does not necessarily make a good 407 RER / cross-regional connection either.
If the goal is build the metro I would work on implementing Ontario Line extensions to Pearson and Markham Centre (Unionville) in the shorter term, and implement the East-West Cross-Regional Connection. If the capacity or performance of VIVA Orange or Purple are limiting, then close the loop on the Ontario Line.