I mean, I know he can't play there due to having a WHL contract, I was talking about WHL being the best development path(As a development league it's well behind OHL for example and also has less results than the Swedish J20 path).
Are we talking about guys drafted out of J20 who were primarily playing there at their draft date or guys who played there at some point?
OHL has a larger pool of players to pull from. Not only does it have the GTA a hotbed of young talent (McDavid, Stamkos, Tavares, Marner, Pietrangelo, Subban) and by far the most populated area in Canada, it also has the rest of Ontario and some big American states it can pull talent from (Michigan being the big one).
The only major difference between the WHL and OHL is the regions they are allocated and the travel. In general, I'd say the OHL's primary advantage predates the kids even entering the OHL, which is the access to high-level coaching, training facilities, and personal coaches based out of Toronto, which is really a hub of hockey-focused trainers (Gary Roberts, Daryl Belfry, BioSteel, etc). So, you could easily argue if you take your argument about him going to Sweden because it has a better track record that he should have just moved to Toronto at 12, played for the Toronto Marlbouroughs AAA program (Tavares, McDavid, Rick Nash, Jason Spezza, Quinn and Jack Hughes and many other NHLers came out of this AAA program, its list of alumni would surpass most European pro-clubs) and worked with the type of private coaches and trainers guys like McDavid and Tavares worked with pre-entering the CHL, combined with the level of AAA hockey in the GTHL that doesn't require the burdensome travel other regions have.
At the end of the day, the path Bedard has chosen should be effective. Its unlikely he is too good for the WHL at any point unless he ends up like Crosby/McDavid (which isn't likely), and then he'll just be there for a year at 17 and in the NHL at 18. Kids being "too good" for junior is often dramatically overstated around here. If someone like Marner can return to the OHL at 18 after averaging 2 points per game, and further round out his game enough to be an impactful NHLer at 19, I would say the list of kids who are "too good" for CHL level hockey is dramatically overstated.