Can't wait to test out the new changes, even if I personally disagree with some of them. It's always good to experiment with changes and see how they function with your playerbase.
Arbitrations are the most fun I've had in Warframe so far. I love the challenge and preparation it takes. I love experimenting and building non-tank frames to be viable in content where a single mistake is all it takes to get knocked out, (Khora & Gara being the most successful). And unlike the majority of opinions other opinions in this thread so far, as an endurance runner, I loved the longer reward times and the challenges that the drones provided (Survival being my favourite, even if it is much less rewarding).
That said, here's my feedback:
I don't like the idea of perma-death being removed. It was part of the challenge of Arbitrations which gave it it's unique flavour. I understand this was in part to deal with Host Migration issues and associated tickets, but I feel like it is an aspect of Warframe that affects the entire game and a larger solution is required.
The revival system, while I don't personally agree with it, needs to be tested in an environment where it can be abused by intentional trolls/griefers. I see a lot of potentially negative experiences coming from the system explained in the post.
As others have said, the stated changes will affect solo players the most as they have no use for squad revives.
Make rewards more meaningful/more frequent. A lot of people are calling for 5-minute rotations to match the ramp up in the speed of enemy scaling. But a good suggestion by jiminatorx that I read recommended AABBCCCC-rotations at 5-minutes but halving the rewards. So players are rewarded more frequently but keeping the current rate of reward.
Make the revival system an optional feature more friendly to player choice. If someone comes into an arbitration unprepared, I want to be able to choose if I want to revive the person or not- and if I choose not to, not to be punished with decreased total health in the process with index-style pickups. Otherwise I like the idea of being able to revive my squad if he/she is worth his weight in gold.
As suggested by ADirtyMonk, to make longer, less rewarding content up-to-par with mission types like Excavation- Introducing Kuva Survival mechanics might be a good solution. So survival/defence missions still reward the same amount of Endo as other mission types.
Thanks for taking the time to read my post.