Is there a Buddhist school / tradition wich recognizes the endless cycle of rebirth but doesn't teach that we should get liberated from it? And even more, that we should embrace it and accept it (while at the same time avoiding the sufferings) ?
Many Mahayana Buddhist traditions believe that liberation is specifically freedom from suffering rather than freedom from being present in the universe.  

But suffering is not to be avoided. It is to be prevented. The avoidance of suffering is what binds us to it.  Recognising it's root causes and eliminating them is the journey to enlightenment.

This is why 'Right View' is so important within Buddhism. When we are able to see that the root cause of our misery is the mistaken view that sees permanence where there is none, sees joy where there is none, and sees self-existence where there is none, then our new view engages in a transvaluation of our experiences.  Because of this transvaluation, our attitude towards some things will invariably change.  For instance, we may look at a new car in a showroom - and just see it as a source of new trouble rather than as a source of joy.

So accepting and embracing the continuum of rebirth is to be encouraged; But to accept and embrace the unmodified, ignorant view of the transitory, empty, miserable shit-hole of the unenlightened state, and holding onto the idea that there is joy to be found in it - that's not a buddhist thing.