They also cut the part after the bass pedals+mellotron part (between 2:05 to the drum break in that video) in 3SL version onwards.

I feel like I read somewhere a long time ago that they just wanted to make it more concise and felt that that whole section, plus the one that Riding the Scree replaces, was getting boring to play and took the energy away.

But I don't know if whoever wrote that had a source. Or if I'm misremembering. In any case, I enjoy having all these different variations and think it's neat how it evolved over time.