Ideally, all players would be re-cycled. If 10 clubs go into receivership, and 10 new clubs start up within days, the players from the bankrupt clubs would simply sign on with new clubs, some might move to existing clubs and others to the new clubs.
It's not a good idea to have the very best players going to start-up clubs, so it makes sense to let them be FA. The money doesn't have to be lost to the overall economy. It can be redistributed in all kinds of other ways.
Right now, many of the players who are being FA listed are not players that were given to a team 5 weeks ago, but are players who have had a little bit of training and started last season. As the salary threshold increases, it will be much rarer for the players being FA listed to be those that were assigned to a team and never having played.
And other players can be recycled as well. In some cases, they could simply take on new identities - countries and names, or if they have been playing BB for some seasons, let them keep their personal history. These players can simply be distributed to new clubs. Over time, this will gradually upgrade the talent given to new clubs to reflect the actual distribution of skills produced by training, and so that the new clubs don't start as far behind existing clubs.