Fired players only become free agents if they have salaries of over $5,000. This was the announcement:
Also, as we announced in the mid-season news, many players who are fired from their teams are no longer going to take to retirement so easily. Fired players (or players who are released from abandoned teams) will list themselves on the transfer market at a starting price of 10 times their initial salary, or 1 million dollars (whichever is smaller). If they can’t find a team interested in them at that price, they will begrudgingly accept retirement. Pro-amateur level players (those with salaries of 5,000 or less) won’t bother with this procedure, as they need to start looking for another job right away. This change is effective as of now.
So that 18 year old 7'5" Hall of Fame $4,995 player who is fired will NOT become a free agent.
Even worse they need to have a salary of $10,000 to become a free agent if their team becomes a bot.