So I did some digging.
On incase's website, dimensions for the old sleeve are noted as 16"" X 11" X 0.50":
https://www.incase.com/shop/sleeves/icon-sleeve-mb-retina-15/heather-grayblack/
On Apple's website, new diamond sleeve is noted as 15.87" X 10.94" X 0.59":
http://www.apple.com/shop/product/H...d-ripstop-for-macbook-pro-thunderbolt-3-usb-c
Those are decimal inches, meaning the differences are negligible in width and length, and could easily be from rounding from the old sleeve. In terms of thickness, the new sleeve actually seems noticeably thicker.
In decimal centimetres:
16" = 40.64cm / 15.87" = 40.31cm (negligible difference).
11" = 27.94cm / 10.94" = 27.79cm (negligible difference).
0.50" = 1.27cm / 0.59" = 1.50cm (negligible difference).
I reckon one site or the other has one of these dimensions wrong, as they're so close as to be virtually identical (try it yourself; pull out a measuring tape and see the differences). They are nothing like what they should be given the 2016 models have distinctly different outer measurements (source: Mactracker app, free iOS+macOS):
13":
2015: 31.40 x 21.90 x 1.80 cm / 1.58 kg.
2016: 30.41 x 21.24 x 1.49 cm / 1.37 kg.
diffs = -0.99 x -0.66 x -0.31 cm / -0.21 kg.
15":
2015: 35.89 x 24.71 x 1.80 cm / 2.04 kg.
2016: 34.93 x 24.07 x 1.55 cm / 1.83 kg.
diffs = -0.96 x -0.64 x -0.25 cm / -0.21 kg.
-------------------- 2015 13" ------------------------- vs. ----------------------------------- 2016 13" ----------------
2015: https://store.storeimages.cdn-apple.com/4974/as-images.apple.com/is/image/AppleInc/aos/published/images/H/L1/HL162/HL162?wid=2000&hei=2000&fmt=jpeg&qlt=95&op_sharpen=0&resMode=bicub&op_usm=0.5,0.5,0,0&iccEmbed=0&layer=comp&.v=1488141974333
2016: https://store.storeimages.cdn-apple....5,0,0&iccEmbed=0&layer=comp&.v=1488141867586
I just don't see it, I'm afraid. In fact the only one I see that's shows a
possible problem, is the last of the 5 images on Apples website:
-------------------- 2015 13" ------------------------- vs. ----------------------------------- 2016 13" ----------------
2015 13": https://store.storeimages.cdn-apple.com/4974/as-images.apple.com/is/image/AppleInc/aos/published/images/H/L1/HL162/HL162_AV4?wid=2000&hei=2000&fmt=jpeg&qlt=95&op_sharpen=0&resMode=bicub&op_usm=0.5,0.5,0,0&iccEmbed=0&layer=comp&.v=1488141962088
2016 13": https://store.storeimages.cdn-apple....5,0,0&iccEmbed=0&layer=comp&.v=1488141845040
These show much more space surrounding the
smaller 2016 13" MBP, compared to the
bigger 2015 13" MBP – bizarre!
But then you look at the same sleeve for the 2016
15" MBP, and the space surrounding it doesn't look so bad:
-------------------- 2016 15" -------------------------
So who the hell knows! Incase are making a mess of things that's for sure. I just wish they'd sodding well get these into the UK/EU Apple stores ASAP, so we're not left still longer hanging on.