Proceeding with order:
All new Icons have been manually crafted from scratch. Probably only the background squircle is the same, but it was manually crafted as well.
The surufy script will work only on icons that are not already present in Yaru/icons directory, so the new icons won’t be replaced (as well as the old ones).
Currently the new icons only appear on Yaru icon set, but we hope that eventually they will be accepted in upstream Suru as well. Initially, the team worked on the applications pre-installed in Ubuntu and currently the direction is to work on all the icon already provided by Gnome upstream.
NOTE: the script is not ready and won’t be probably ready for the next release (at least not pre-installed). I plan to write more about the current status in a separated thread.