That's actually not true, and it surprises me people still think like this.
Each year most of the players who change clubs are under contracted and released early. It happens a lot. Clubs changings coaches, tactics or players needing a fresh start and a club happy to offload them.
Blore wasn't available this year, Neither was Papalii...
Matterson in 2020, Aloiai before that....
Offer a player a reason and money, Most are available.