I think you are right. I don't know how much of a scene it will actually be. For all we know, it could be as simple as the GotG messing around and then Rocket pressing a "button" and we launch off.
Also, one thing to wonder about is how the firing of James Gunn will impact this ride. The main reason (from what i've heard) that the ride wasn't going to open until 2021 is that they were going to wait until GotGv3 started production to film the ride portions. Now with Gunn's wit out of the picture and a potential pushback in production, it'll be interesting if it has an impact on this project or not.