I was kind of hoping for an iMac update too. Not anything important, but move it to USB-C so it's in line.
Just upgraded the SSD in it from the fusion drive to a full on SSD, and it is incredibly fast now.
Probably not, they really seem dead-set against touch interfaces of macOS, and have made pretty much no improvement to it towards that end.
I had one laptop with a touchscreen and it was so annoying that I disabled it. Every time I would brush something off of the screen, or someone would point at my screen and touch it, unexpected things would happen. Keyboards are much more efficient than touchscreens, so there didn't seem to be any point.