Bought a brand new Breville Barista Express.
Was flushing the machine, running water through steamer, hot water spout and group head until I emptied the entire water tank.
I noticed fine white flakes in the cup I was using and figured out they were coming from the steamer wand. After about 5 rounds I saw them showing, and they seemed to have dissipated now after a few more flushes. But, what is it, could it be scale even if it's a brand new machine? Unsure if this is normal or a problem with the machine we bought.

Most likely they are packing materials. Usually, scale doesn't first show up as flakes in the the cup, since it sticks to the metal surfaces; machines mostly clog and break down long before bits of scale break off.