They extended 188.8.131.52 a few years ago as well. 184.108.40.206 was released in April 2011, with premier support ending in April 2016. Premier support was extended by two years, and now ends April 2018.
I believe that 220.127.116.11 was released in February 2015, so the natural premier support ends February 2020, and is now extended ten months to December 2020? That seems a little arbitrary, I guess they they just rounded two months down to make the date easy to remember? 18.104.22.168 was extended too.
Sure, this *could* be related to future release plans, but I don't think that's a foregone conclusion.