I think more than EF are using versions of the shakedry jacket, at least quite a few are using mostly black very thin jackets at times. I think it depends a fair bit on the rider as well – if you’re just chilling in the groupetto you can easily deal with receiving/handing back a bulkier jacket from the team car and probably need the warmth more (and aren’t so bothered about it being slightly less aero). In a breakaway or GC battle though they often need something packable if there’s a few mountains in succession and care more about being aero for the last bit if it’s not a mountain top finish.
It’s the general lack of anything but mitts (and often bare hands) that surprises me, surely pro riders could easily get accustomed to the bulk and feel of heavier gloves for cold/wet stages and be happy to use them from the start? Maybe it’s just my occasional riding mamil viewpoint but I’ll happy use bulky gloves if it avoids painfully cold numb hands (even more so if I was descending off a mountain and wanted to be in control of my braking).