I see where you're coming from, but I'm... disinclined to agree with you. Structurally, they both occupy a space where a chorus might be, but the melodies don't even echo each other. Vocally and lyrically they've got nothing to do with each other, and there's not a huge echo musically, either. Plus there's that big break where they cut to the chuggy verse riff in the first section... I think a chorus requires some degree of distinct, striking commonality - I get that they can accommodate changes melodically, lyrically, musically, all of that, but they generally mirror each other a lot more than the Metropolis passages do.
They might be pseudo-choruses, they might be filling a similar function to a chorus, but I think that's stretching the definition of a chorus way past its natural limit.
Good thinking point, though! Music's so instinctive, so subjective and frankly formless that trying to slap words all over it does become a little meaningless after a while. It's like the track/song/suite argument for Six Degrees. People insist that it's wrong to evaluate Solitary Shell on its own because it's part of SDoiT - but does that mean it's wrong to listen to it on its own? What about when it's on a setlist, is it half of a song then? Because it works out of context. It's got an extended solo and everything! Even on disc, it's got a distinctive verse, chorus, verse, chorus, solo structure. I say Six Degrees is a song - and while I say Solitary Shell is part of a song, I'd also insist that it's a song unto itself. It's a track, and a song, and a movement, and an excerpt, and all of those things, and it's frankly a completely stupid thing to take either side over.
If someone insists that I am not allowed to refer to Solitary Shell as a song, I will insist they are wrong. If they insist that I have to refer to it as a song, they are equally wrong, because it's part of SDoiT. Music's more fluid than the way we talk about it, and trying to impose any one definition upon a grey area is always ridiculous! So I'm not saying you're wrong about Metropolis' chorus. You're just a different kind of right to me. q: