The Sky Q UHD is probably still SDR as first gen Sky Q boxes can't do HDR, and I don't think they can tone map Rec 2020 HLG to Rec 709.
It was reported Sky were planning live HLG HDR in time for the Olympics next summer, although it wasn't stated whether that would be the BBC or Eurosport's coverage.
The same report said Sky productions and movies are due before the end of the year to add to their currently (very) limited selection available.
Is this Eurosport French Open coverage the first HLG HDR broadcasts in the UK, or have their been previous ones? (Not counting anything streamed).
Good that Eurosport Player is now 50p, that's another one doing the right thing.
Sky are already doing UHD HDR using HLG via downloads on compatible Sky Q UHD boxes.
I guess the issue they have with live is that they either have to simulcast two UHD HDR streams (One Rec 709 SDR for first gen Sky Q UHD boxes that do Rec 709 SDR UHD only, and one Rec 2020 UHD HDR stream) or ditch the UHD stream for first gen box owners?
Although HLG is backwards compatible with SDR displays - that's only within the same colour gamut - and HDR really needs Rec 2020 Wide Colour Gamut alongside it to be worthwhile.
Interesting comparing Eurosport HD and Eurosport UHD on Sky Q during the French Open. The Eurosport UHD SDR feed is showing some tone mapping artefacts on some players orange shirts, which you don't see on the HD SDR feed. (My guess is that they are either using two different tone mapping approaches - or that the French Open is using Sony cameras with Rec 709 HD SDR and Rec 2020 UHD HDR dual outputs from their BPUs or CCUs and simul-cutting in parallel to avoid the Rec 709 HD SDR stream being a downconversion and tonemap from the Rec 2020 UHD HDR feed, downstream of the cameras)