I agree. It won't interoperate at all. At best Jane will go to Bloor.I feel like at this point any attempt branch off of the Eglinton Line won't really end up working out well, especially on the west end. The Eglinton West Subway is a project that carries a lot of weight on its shoulders. Not only will it be a major way for people from Etobicoke and Mississauga to get to Pearson Airport, but it will connect to a major transitway going to Mississauga (and that will eventually have a downtown subway under S1), and the entire corridor is planned to have a ton of density as part of the TOC initiative done by the province. Finally this is going to be the primary route linking Mississauga and Midtown Toronto. Some time ago, Reece Martin had an interview with Phil Verster, and during that interview Phil something very interesting, where he talked about the need to be commercially astute with transit projects, and seeing where to cut out the fat. Now a direct example he gave was the cancelling of the Scarborough Junction project and the realignment of the LSE corridor tracks, but he also brought up the lack of needing to build the Missing Link, and that Milton RER could be provided via other more fiscally conservative means. The way I personally interpreted this is that in some ways it seems like Metrolinx is seemingly looking at Eglinton West as a replacement for Milton RER, on top of all of its other responsibilities.
Now what is my point with all of this? In short, I really don't see a scenerio in which the Jane LRT interoperating with Eglinton ever happens. Eglinton is already going to suffer from serious capacity limitations due to the vehicle types, and has a limit to how frequently trains can arrive due to the existence of the at grade segment in Scarborough so its unlikely we're going to see trains arriving at headways sooner than every 4 mins. Maybe if Sunnybrooke Park gets some extremely strong signal priority or gets grade separated, we can have the core section of the Eglinton Line between Jane and Don Mills running at every 2 minutes, which would leave Jane and Eglinton West at 4 minute headways, but even then I'm not sure if this is enough to handle the demand for Eglinton West in 30 years time. In short, if we choose to build Jane as an LRT, I highly doubt we have any room to squeeze the trains onto Eglinton. Best case scenerio we might see Jane parallel the Eglinton Line until Mt. Dennis, either on Eglinton or along the Kitchener Line corridor with the line connecting to the Mt. Dennis MSF, and maybe we can install a connecting track between the two in case we need to move trains around for various operational needs, however this is by no means anywhere reaching a necessity, and at best you're redoing the signaling on a Line just in the off chance you need to move a train around.