A lot of the FAs seen early on are old because they'll be the 'filler' players added in the new season for out of contracts.
At top of the server FAs will, more often than not, need to come from same or higher level teams so chances are lower with fewer teams.
Additionally if teams keep them longer then they'll be less viable - older again.
No idea if 'repo' players are put on as FAs or just destroyed.
Just guessing and putting off going to make dinner XD Better go now.