That sounds totally bogus. You don't have to update the BIOS to support Ryzen. Ryzen is the first CPU on AM4.
You don't need "DDR4-2133 sticks". Ever. Any DDR4 sticks can run at 2133, that's literally the DDR4 standard, everything above is overclocking. 2133 rated sticks are the cheapest (and worst).
I got my R7 1700 and mainboard yesterday. Everything worked on first try. Speaking of DDR4, my 2400 rated (Hynix) sticks overclocked to 3200, with decent timings, even :) (Well, decent for Hynix.) My previous system (overclocked non-K Skylake) couldn't run these sticks above 2450.
You can, before simply defending AMD, research and see for yourself that required BIOS updates are indeed an issue.
I tried it with an MSI Tomahawk, and an Asus B350 Prime. Had a Ryzen-5-1600 and a Ryzen-7-1700, as well as a pair of DDR4-2133, and DDR4-3000 modules each, and tried every combination, and was never able to post.
Switched to Intel CPU and Asus Intel-supporting MB with the same DDR4-3000 RAM and POST'd on the first try. I'm saying that to 'prove' that the other components were fine.
I'm glad that it worked out for you, and I wish it had gone smooth for me too.
http://www.tomshardware.com/answers/id-3387164/am4-motherboa...
https://www.reddit.com/r/Amd/comments/66b7vu/to_all_ryzen_5_...
... so many of these.
But be warned: Motherboards that "support" Ryzen do not in fact support Ryzen out of the box. You have to update the BIOS to support Ryzen. How do you POST without a CPU you ask? Who knows? Magic, possibly.
I still don't understand how AMD expects their customers to have more than one CPU (and possibly DDR4-2133 sticks) to be able to POST and update the BIOS.
I returned everything AMD and went back to safe, good ole Intel. Worked on first try. I'm never getting sucked into AMD hype again.
Also, when I went back to return the AMD components to Fry's, the manager said they were aware/used to getting Ryzen returns because of this.