Well, the process of research and discovery can itself be enjoyable. That said, I don't feel that there is a need to hold onto our current enjoyable activities if a CEV can create novel superior ways for us to have fun.

I would posit that divergent behaviors and approaches to the norms will still occur, despite the existence of such an oracle just for the sake of imagination, exploration, and the enjoyment of the process itself. Such oracle would also be aware of the existence of unknown future factors, and the benefits of diverse approaches to problems in the face of factors with unknown long term benefits and viability until certain processes has been executed. As you said, such an oracle would then try to explore every avenue of research, while still focusing on the ones deemed most likely to be fruitful. Such oracle should also be good on self-reflection, and able to question its own approaches and the various perspectives it is able to subsume. After all, isn't self introspection and self reflections part of how one improve themselves?

Then there's the Fun theory sequence that DSimon have posted about.