TDAS was meant to have many nods to past challenges. Here's a list of challenges I feel were missed this year:
TDI: Dodgeball, the cooking challenge, tri-armed challenge, the bike race, and something similar to the psycho killer challenge
TDA: Super hero challenge (come on, it's HEROS VS VILLAINS!), spy challenge, space challenge, jail challenge, western challenge, and most importantly, DISASTER CHALLENGE!
TDWT: Pinball from Japan, Greece challenges, roller coaster thing from Jamica
TDRI: Backstabbers Ahoy, Grand Chef Auto, Getting to know you, totem pole race, climbing the mountain from Ice Ice Baby
Yeah so here's a list of challenges I think would have been cool to repeat, however I understand there would be no way to fit these all in the season. Comment what challenges you would have liked to see in TDAS!