It's probably for product segmentation when/if AMD releases lower end sku's like the 5600 ~5700x.I'm on 1.2.0.0 even though it lets me go +400MHz or +500MHz in the BIOS it no longer translate through when I check the clockspeeds or if I go Ryzen Master its just +200MHz.
Slightly annoying they have done this as its overclocking and surely outside the warranty whether its +200MHz or +500MHz and its not like you Ryzen Master stops you putting in silly multipliers or voltages, mine seemed rock solid at 5050Mhz also with a -14 curve
Maybe also to reduce RMA if people push their CPUs to hard.