Technically if someone decides to go to the park and part of their reason for doing so is because they want to ride Mr. Toad, then Mr. Toad helped generate +1 ticket sale.
Also, considering how small and simple the attraction is, it'd really take some unique circumstances for anything to happen to it, I think. Let me transition into a story from my days as a CM:
Often times, attractions would compete with one another to see who can get more hourly Guest counts. The battle would take place over a few weeks or so and in the end, the attraction who pushed more people through would get a reward (something as small as an Ice Cream party or as big as a walkthrough of a different attraction after closing). Attractions were paired against "fair" opponents with similar hourly capacity.
At Winnie the Pooh, our opponent was always Mr. Toad. So think about that for a moment. That means Pooh, who takes up way more real estate and has a much larger show building in back, pulls in about the same numbers as Toad.
To me, that means Disney won't touch Mr. Toad (unless to plus it) for any sort of removal or total replacement before they hit something like Pooh, which gives them much more to work with (-and a conveniently placed gift shop to exploit at the exit). Even if Toad doesn't bring in "big bucks" on merch sales, changing it to something else may be more trouble than it's worth given it's connection to rides that do (Alice) and it's overall size and placement.