With Valve's blessing, it seems the Half-Life 2 series is getting a full update from the team that made Half-Life 2: Update in the form of the Half-Life 2: Remastered Collection.
You can see the entry up on SteamDB, with a Steam page not yet live. However, this has actually been listed since May 2020 so why is it getting noticed again now? It seems Tyler McVicker, known for doing the Valve News Network which is now just under McVicker's name, posted on Twitter noting that it will include the additional episodes too and in a later Twitter post McVicker mentioned speaking to the team behind it to confirm it is indeed legitimate.
For people who are still somehow yet to play through Half-Life 2 and the episodes, perhaps this Half-Life 2: Remastered Collection might end up being the best way.
Whenever we see more information on it, we'll let you know.