Humble Store gets an official site now: https://www.humblebundle.com/store
GOG, are you still sleeping?
I only see nine games there and you cannot even narrow down the search to DRM free but if you could it would be only four. However they have Linux although they probably do not offer support themselves.
So, I think from a neutral point of view GOG is hurting itself by not offersing some Linux support, if not much by means of actual sales then surely by reputation and also being an easy target for criticism.
They are surely not sleeping but they don't give the impression of being extremely agile, innovative ... ahead of the curve.
For improving the general situation regarding Linux gaming the new store is surely a step forward and increases the pressure on GOG to also do something. How much pressure exactly and if Linux games will ever come to GOG in the near future... remains a secret to us.