This offer has been extended to the newly launched Pixel 2 and Pixel 2 XL handsets, but unfortunately it seems that this is not a free-for-life offer. According to Google’s fine print on the Pixel 2 page (via Android Central), it seems that this free unlimited storage will only be valid until the end of 2020.
It reads, “Free, unlimited original-quality storage for photos and videos taken with Pixel through the end of 2020, and free, unlimited high-quality storage for photos taken with Pixel afterwards.” Note that this date is for the US because for other markets that the Pixel 2 phones are launching in, the cut-off date is different due to a later release, like in Canada and India where the cut-off has been listed for the 15th of January, 2021.
We suppose free-for-life was too good to be true, but either way it’s something to take into consideration especially if you foresee yourself using Google’s services for many years to come.