Could MLSE make a deal with a prospective owner to bring in a GTA2 team? Sure, The real question is will they? Anything is possible, but again... the best time to do something like that was between 1967 and 1995. Franchise and market values started going way up, and it just doesn't seem likely to me that MLSE will allow a team into their market at a discount.
Let's say you own a large plot of land. Maybe you have picnics by a pond, you have woods on your land you go hunting in, or maybe you just enjoy taking time at night to stargaze. Someone comes along, knocks on your door, and asks you to sell them the right to use half of your land in perpetuity. Your land is valuable, not just to you, but because of what you have on that land. Are you gonna give them a sweetheart deal, or will you tell them to pay your asking price or sod off?
The idea MLSE will give someone a sweetheart deal to add GTA2 is preposterous at best. There's a better chance of the NFL awarding a franchise to Toronto.
While I'm not a fan of any scenario where a play-in is added for the bubble teams, I can see why the league might consider it. Especially in the likely event that expansion to 34+ also results in revamping the playoffs.