Autofilled in promos after positional ranked removal

I just got autofilled in my gold 4 promos. I read the ranked gameplay FAQ (https://support.riotgames.com/hc/en-us/articles/204010760#h6q1), and it specifically stated that autofill will not happen during promos. Why did I get autofilled despite what the ranked gameplay FAQ said?

Note: I usually queue adc/mid, and I got autofilled support in my first promo game in my promo series from silver 1 to gold 4.