How can 1000th place pay $50 in a $20K freeroll that is $50,000 in prizes if they paid all places $50. It is more likely $5 for 1000th place or $50 for 100th place.
Also Bet365 is hosting this tourney not the Prima Poker network. In May the $10,000 freerolls had around 3700+- entrants, about the same as their $5,000 sat freerolls.
No catches. My winnings were cashable and no raked hands to withdraw.