I see a lot of great changes like the reduction of super long endless missions. Thanks for listening to our feedback.
However, I worry that the new challenge "Complete a Spy mission using your Operator. Warframe cannot leave spawn room." is definitely going to spoil Operators and the Second Dream/The War Within for new players. Those quests were such a hype moment for me and it would be a real shame if players got those quests spoiled for them.
Maybe the challenge could be to complete a Spy mission without triggering alarms and without turning invisible. Other possible challenges could be to win an Interception round without losing a single point, complete a hijack mission without leaving the payload, play (not win) 3 games of Conclave, get X score on Flappy Zephyr/Wyrmius.