If there is no Chakra - Then there will be no Ninjas - There will be no Shinobi system - There will be no village system. Thus there must be something to replace it.
Which was the goal of Obito when he was in pursuit of Infinite Tsukuyomi.
Some more points that are very weird if you ask me :-
1) The Mecha art was given at the chapter when Madara won against Sasuke and Naruto. The chapter 662 was titled "the real end" or end of reality as the saviours of the world lost and Madara won.
2) The Mecha art hints at the possibility that No human in the genjutsu has a will and is basically a machine or a robot. They all basically share the same will as Madara and obey him hinting at the Mecha theme art.
3) It raises the hope that both Naruto and Sasuke would fight against Madra's will and defeat only to be faced with a greater evil, i.e: The Fruit of the Shinju.
You answered your own question. The 2nd point is what the mecha art exactly means.
OT: I don't see this happening cause I don't see the manga progressing to show us the dream world to this extent when I already think we won't be seeing it at all.
I want to say yes, but Kishi did write the Naruto Road to the Ninja movie and he sad he was using stuff he couldn't fit in the manga. So if he wrote a movie based on that arc, then I dunno. We might get trolled after all the hype for IT.
This may happen but I doubt it that Sasuke and Naruto with powers from the sage aren't going to beat Madara in this arc. I think the next arc which is likely to be the last one will focus on Sasuke and Naruto and the village,their friendship or maybe a time skip to the future where they are Hokages or whatever.
Likely, but a huge plot hole will emerge, What was the purpose of the Juubi's Fruit ? I don't see Kishi just leaving it considering that the Fruit of the Shinju is the basis of the story.
That wouldn't be the first time a plot hole appears . And isn't the purpose getting power? It was for Kaguya.
hmm....this is very different