Content from collapsing items can render 'below the fold' should the behaviour be to push them above the fold so users can see or is auto scrolling worse experience?
In most cases it shouldn't.
Such forcible pushing would be a worse solution. The better option would be to leave a focus at the current location and clearly indicate that the view has been opened below. It's very important since user might click that button while it's at the very bottom of the screen, making a newly opened panel unseen.
While in the second the whole panel is clickable, though only a + sign on the right hand side changes to -, that may not clearly indicate the state transition of the panel. The indication seems to be done better in the first example due to fact that the color of the button is changed, clearly indicating its toggling.
It depends, on the kind of content that's in there.
For example if its a comments sections then it would be a better experience to see the last comment made if there were a lot of comments. If it was some static information that needs to be read from the beginning. then auto scroll isn't a good idea.
whichever you decide it would be good to provide a link or button to "go to top" or jump to the end.