The BF deals are already here (but not advertised afaict) and some differences compared to years past (mail and unlimited for instance are offering the deepest discounts on the 1yr sub instead of the 2 yr sub)
Yes, you were thinking of mail plus (1.99/mo for a year) VPN black friday deal is 2.99/mo for 2 years).
Regardless, one thing to be aware of is Proton’s deals are not recurring. You don’t get a locked in price, so a slightly higher price on a 2yr plan might be more cost effective than a deeper discount on a 1 year plan, and after the term expires it reverts to full price.
Based on what I know, I choose to think of any Proton discounts as “introductory offers” (nice if you needed just a little extra encouragement to subscribe to Proton, but not a meaningful discount over the longterm)