You realise the rider photographed deliberately did that to draw attention to body fairings situation (and successfully so as it’s banned in non-UCI time trialling in the UK as a result).
At WT level we still have body fairings to a more subtle degree with radios down the chest wrapped in material, which on certain riders will have meaningful aero advantage. The new Giro helmet will have similar benefit to an existing TT helmet on some riders, and on others it will be slower - but anything that visually pushes the aesthetic from Eddy Merckx 70’s TT look will get banned by the UCI if they ‘feel’ like it.