I will miss Kanonen a little. I know it wasn't everyone's favourite but for me, it was a decent little launch coaster that managed to be quite thrilling despite its tiny footprint. Hopefully, it will go onto a new life as a smaller park's signature coaster. It's not often that you see a custom layout Intamin rocket coaster on the used ride market. It's only 11 years old too.
Liseberg do have some form when it comes to removing rides relatively early in their life. It seems they really don't mess around when it comes to refreshing their ride lineup. HangOver lasted all of 5 years. It says a lot that although the park opened in 1923, their oldest ride dates from the 70s.
While I am a little sad about losing Kanonen, I'm far more excited about what will be replacing it. Much like Phantasialand, when Liseberg close a ride or start a new construction project, you don't worry because you have confidence that the park will produce a quality attraction that improves the guest experience and moves the park forwards.