It means that Rolex has changed the pattern of the serial numbers they assign to their watches --its now a random pattern (or a scrambled number). Its nothing that needs to be avoided; all newer Rolex watches have this random serial number pattern.

What does scrambled mean in watches?

Starting about mid-way through 2010, Rolex started to “scramble” the serial numbers. These are also known as “random serials” or “scattered serials” and are not as bad as they sound. It just means its a watch from after 2010 that Rolex began implementing this new serial number system with.