You are right mate, CZ doesn't need to gain back his position as a CEO for the exchange to function well. As the former CEO, he still have some contributions to make that will still help impact the exchange positively.
He can still remain influential and help guide the company to some better decisions off the records
because his inputs brought the company far and is still valid.
Time in custody has definitely provided him some more clarity, as he has had more time to think away from distractions and disturbances.
Yes, he has built the company from scratch and raised it to a great length, before the issue that lead him to serve for some month came up. Since he is out, he can still give good inputs without being the CEO.