As the other have said, it’s not a must to neuter a male like it is with a female. It varies from bunny to bunny how bad their hormonal behaviors get and how much they improve after neutering. Generally I would say that most bunnies with undesirable behaviors do improve a lot afterwards but it’s not guaranteed.
Our boy had taken to pooping and peeing all over the floor every time we let him out of the cage. The moment he got home from the neuter he stopped that completely and went back to almost perfect litter habits. It was an immediate turnaround that shocked both Hubby and me. Normally it takes about a month for the hormones to even out though.
I also think that it’s beneficial to them psychologically. Intact males are always on the hunt which can become stressful and frustrating for them. Once you take that urge away they are able to become much more relaxed and also allows them to bond closer with their humans.
Everybody has their own opinions on the subject.