Tuition dependent colleges with large transfer populations should be preparing now for the possibility of free community college. Politicians at various locations on the ideological spectrum have been talking about this so some version of it could happen in the foreseeable future.

Colleges with discounted price points in the $10-$20k neighborhood might need to be especially attentive. On the one hand, their supply of four year students could drop drastically. And on the other, they could face increased competition for degree completers who began their careers at CCs.

If the balance of their enrollment tips toward degree completion, the repertoire of courses and course sizes that they'll need to have in the field could shift and the transition to that arrangement might involve higher costs when enrollment in lower division courses is not small enough to eliminate them but demand for upper division courses requires more of them to be taught.

This could create the reverse of the "too many majors" requiring too many small advanced courses to be taught problem. All of the sudden you will still need to field intro courses for the few four year students you have while upper division courses which might need to be smaller due to pedagogical considerations start to multiply.

These things are eminently model-able and projectable, but one guesses few places are up to the task or are forward enough thinking to engage in this kind of work until it's too late.