[cromka]

Does it also show each patch involved?

[OJFord]

It shows the overall diff since last update, not patch-wise. But it does show any extra patch file, install script, etc. – not just the PKGBUILD – if that's what you meant.

[gpm]

The manager I use (paru) does, I'd be surprised if yay doesn't.

[Charon77]

It does, but there's a y/n question of whether you want to see the patch