Got the mail too, fortunately I've chatted with support so the situation is clear for me but it's really great to have some typos in a subject as sensitive as price change / increase.
So, if you were on FairSaas for few years ( before v8 ) like me, with 1WS+3RN ( one workstation license + 3 render nodes ), you're migrated to the Corona Premium plan. I was already on the annual plan so I don't know if customers with monthly plans are migrated on the monthly or the yearly, since the price difference between both is quite massive now. Also, and if you keep the subscription active without interruption, you keep the 3 render nodes from FairSaaS "at no extra cost". And yes I'm using quotation marks because the new plan is more expensive than the new one - 44,42% exactly, twice the inflation since 2015 -, and if like me you don't need the features included in premium like Scans and Phoenix, it's not a great value.
Come on guys, Phoenix is not even available on Cinema 4D !!! Who came up with these new subscription plans, a random guy in marketing departement with no clues about the software ?