Yep, '3' addresses are not new for segwit.
The first block we found on the pool included a '3' address in the payout.
To be clear about that

It's not new at all, since segwit, by definition, is a bug fix for P2SH - and P2SH is where the '3' addresses come from.
One of the problems with segwit is that it isn't just the segregated witness bug fix for malleability, there's a whole bunch of other shit in there that, no doubt, many will come to regret accepting ... and some will not realise they did accept in the first place

But for the segwit part of P2SH, well what I'm (still) running on wallets and mining everywhere is a modified bip91, and bip91 is core 0.14.2 with minor changes.
So there should be no problems with what is apparently called P2SH-P2WPKH addresses

Thank you Kano , just wanted to confirm before I changed my payout address. You will see on my account it has now been changed to a "3" address.
Weather is cooling down on Lab city so my hashrate should be getting higher over the next few days