First of all - Congratulations!
It's hard when you are so happy you want to shout it from the rooftops and that is not feasible...so feel free to crow and preen here, in this safe and anonymous forum.
Second of all - one of my first thoughts is that this polyship is still very, very new - just one month old. I am so very glad that so far things have worked out well but you all are likely still in the throes of NRE (New Relatonship Energy) - which is a time for exuberance and romance and lots of fun stuff, BUT it is also a time when we tend to see everything through rose-colored glasses, we assume that the people we care about (friends/family especially) will OF COURSE be just delighted with our new-found love, that OF COURSE we will always be together and live happily-ever-after, etc. (Not saying that these things may not come to pass...just that NRE tends to lend itself to optimism...)
In a polyship there are multiple relationships that need care and feeding to grow healthily (A+B+C, A+B, A+C, B+C - as well as each persons relationship with themself as they learn who they are within
each of these relationship (GalaGirl has written some excellent posts here about "polymath"). You all may want to take this time before you are "out" to really be able to focus on all of these relationships without the added stress of having to deal with other people's (friends/family) possibly negative reactions.
It would, IMO, be a shame if the "coming out" process strained the beautiful thing that you are building at this early stage. Take time. Breathe. Let NRE run it's course. No need to make sweeping public declarations (even though you are BURSTING with joy). There is all the time in the world for that...later.
Due to my profession I will never be "out" publically while I am still working.
We are "out" to our friends - they all figured it out on their own within a few months. No sweeping statements - we've talked about it to various degrees when it came up in conversation or when they've had questions. (PS. nobody was particularly surprised - they've all known us for a very long time)
We are not "out" to our families - although some of them likely "know" already, no one is talking about it. We did recently disclose to all of our immediate families that Dude is now "officially" living with us for an indefinite period of time (he has been "unofficially" living with us for a year now). I'm guessing the rest will figure it out once he's been here 5-10 years
Just my (rather long) 2 cents.