Today, Guardians was $15 and EPCOT LL was $19. If Disney removes the individual LL and X is number of guests per day that use ILL then Disney would ose $15X day.
If Disney instead moved individual LL spots into added Genie+ capacity then they'd need to sell Y number G+ more subscriptions. Y = $15X/$19 = 0.78497X more EPCOT G+ subscriptions to break even on the SWITCH, so with these numbers if Disney can sell more then the ride would make more money as a G+ attraction, and that's if costs remain same.
At a $15/$19 split the bet is whether Disney can convert more than 78.5% of daily Guardians ILL purchases to incremental G+ purchases. Maybe a high number considering that some buy both and couldn't be double counted, but offset to some degree by people that didn't buy G+ but see new value in the service including Guardians. Those are subjective guesses for us without the real numbers.
But I don't think it's realistic that price would remain $19. For argument let's say it bumps to something like $21 so now value of moving Guardians to G+ is not just from converting some purchases of $15 ILL to $21 G+, but then Disney makes more money from everyone else that was buys G+ regardless of Guardians inclusion.
About Bayou Adventure, I think the demand will be more acute at MK when Bayou Adventure opens as anyone that wants to ride that didn't get a VQ, or that wants to ride twice, will pay more than the $27 MK was today. After BA opens I'm not sure we'll ever see MK and multipark G+ under $30 again. And because multipark is priced same as MK, Tiana demand pushing up cost of MK G+ will push up multipark G+.
Short answer: I think moving Guardians to G+ would set a new higher floor for EPCOT Genie+. That plus the number of people migrating from a lower priced ILL to a higher priced G+ would all offset the loss of Guardians as a separate ILL. I think the only reason they haven't is because they're beholden to something as ILL in each park. And I'm willing to accept that I may be so far off that I'm not even swinging in the same ballpark.