How fast would you like it to crack?
Drystack walls without mortared joints are somewhat tolerant of frost movement. Many landscaping wall block systems intended to perform that wall function are out there, as well as actual drystone walls from natural stone.
Mortared joints will break unless sitting on a solid foundation that does not move.
That does not ...
NM can be in the hollow cavity’s of block walls but not embedded in a cutout.
When run in block walls, if exiting the wall conduit would be needed on the outside unless a surface covering is provided (a furring strip on either side with 1/2” plywood or Sheetrock) is another way to do it. Your actual work might provide more detail.