^Just to add to what you posted above. The season is filming right now
Challenge CBS Confirmed CastLocation: Argentina
Host: TJ Lavin
Sarah - Survivor: Cagayan
Tasha - Survivor: Cagayan
Desi - Survivor: Heroes vs. Healers vs. Hustlers
Angela - Big Brother: Season 20
Cely - Love Island: Season 2
Justine - Love Island: Season 2
Kyra - Love Island: Season 2
Cashay - Love Island: Season 3
Shannon - Love Island: Season 3
Alyssa - Big Brother: Season 23
Azah - Big Brother: Season 23
Tiffany - Big Brother: Season 23
Shan - Survivor: Season 41
Cayla - The Amazing Race: Season 33
Tyson - Survivor: Tocantins
Enzo - Big Brother: Season 12
Leo - The Amazing Race: Season 23
Ben - Survivor: Heroes vs. Healers vs. Hustlers
Domenick - Survivor: Ghost Island
David - Big Brother: Season 21
Cashel - Love Island: Season 1
James - The Amazing Race: Season 32
Cinco - Love Island: Season 3
Javonny - Love Island: Season 3
Derek X - Big Brother: Season 23
Kyland - Big Brother: Season 23
Xavier - Big Brother: Season 23
Danny - Survivor: Season 41
As you can see from the list, this challenge only features cast members from 4 CBS shows: Big Brother, Survivor, Amazing Race and Love Island.
MTV challenge veterans were considered for this when this show was in the early stages of its development, but at some point production changed their minds and decided not to include them on this, which is ironic since we've seen cast members from CBS shows cross over to MTV's the challenge