Half-Life 2 Fan-Made Remaster Seemingly Coming to Steam With Valve's Permission - IGN - IGN

According to its Steam DB page, Half-Life 2 Remastered Collection is not being developed by Valve, but instead, by Filip Victor, a modder who developed the Half-Life: Update mod that launched on the Steam store in 2015.

Mcvicker said that he is "able to confirm" the legitimacy of the project and that it is "being made by the former Half-Life 2: Update team".

I have been able to confirm this projects legitimacy, being made by the former Half-Life 2: Update team.

Whilst modders have continued to work on Half-Life 2 over the years, Valve its self returned to the series with Half-Life: Alyx - the company's first take on Half-Life meets VR.