So far as the data we have in-hand is concerned, it isn't even very likely that the universe is destined to collapse in the future. There is no convincing evidence that shows the universe has 'greater than critical' density for this to happen. As for the inevitability of a 'bounce' after a future Big Crunch, this requires following the universe as its space-time evolves beyond a future Singularity phase. We do not know how to do this. In fact, all we can guess is that the universe enters some kind of quantum state like the one it emerged from at the Big Bang. We have no way of predicting the properties of a universe than emerges from such a state, nor do we know if such a forecast is even possible theoretically.
Any argument that you might have about how reasonable an Oscillatory Universe is, is based on intuitions about how nature works that are mostly irrelevant at the extreme conditions that will prevail at the time of the 'bounce'. General relativity promises an oscillatory universe as one of the many solutions of the universe, but we have know since the 1920s that 'classical' general relativity must give way to a self-consistent quantum theory of gravity. In even the simplest versions of such a theory, time no longer behaves as a continuous parameter through the quantum regime. This is why we say that spacer and time come to an end at the Big Bang, just as they will at any future Big Crunch. They cannot be 'analytically continued' as real-valued variables beyond these end-states, so there is no time axis on which to symmetrically construct an oscillating universe beyond the present expansion/contraction event...if contraction will even occur in the future which seems very doubtful.