I believe this to be inaccurate.
I saw a nice post a few months back that went into the reasons in detail, but I can't search for it.
There is a clause in the approved PoR which stipulated cash to equity was to be shared 75/25 between Class 19 and Class 21.
For every dollar that goes to equity, 75 cents will go to the Preferred class, and 25 cents will go to the Common class. If you're super interested in the details, the post with the details was probably in late Feb/early March.