As per suggestions by the previous comment, I tried to launch other objects. Minecarts are launched, as are any mobs/players in the cart (be it creative or survival mode).
An observation I made while being launched in a cart: Note the 4 corners in the shape I built. The height you get launched varies, depending on which corner you are close to, with the North West launching to the highest altitude, and the South East launching to the lowest. This might be related to the South-East rule (https://minecraft.gamepedia.com/South-east_rule), but regardless, the main point of this bug is that players are not launched in survival, and neither are mobs.
Adding on here that I got the same issue. This is my testing setup: https://i.imgur.com/hLRvotn.png
I also found out that the launcher works in survival, on mobs and players, if they are inside a cart.