If there's one thing Half-Life fans have accepted, it's that Gordon Freeman's life is uncertain now. At least, until Half-Life: Alyx came out. One of the aspects to the game is that while it is a VR title set in the Half-Life universe, it is meant to not be a prequel or a sequel of any sort. It was designed to be a story told in the middle of the original first two games. However, the ending of the game may have changed the course of history. Below is an excerpt from Road To VR written by Ben Lang, which is spoiler heavy. So if you don't want to know what's up with the ending of the game, this is where you turn around and go back to playing it.
The end of Half-Life: Alyx very significantly changes the ending of Half-Life 2: Episode 2. G-Man shows Alyx that fateful day in her future and gives her the chance to change the outcome. She does, and prevents the death of her father, Eli Vance. If you wait out the credits, you return to the scene where Eli was just saved, this time as Gordon Freeman. While at the end of Half-Life 2: Episode 2, Gordon and Alyx were just about to head off to find and destroy the research vessel Borealis, this time Alyx is nowhere in sight. Eli is angry and wants to set off right away apparently to rescue Alyx and hands Gordon his iconic crowbar saying "Come on Gordon, we've got work to do." As the player, you grab the crowbar and hold it for just a brief moment before the scene fades out.
So basically, the end of the game makes a change in time, altering the ending and making it so that Gordon is now on a new mission. In other words, provided they decided to do it, the devs just gave themselves an open door to go make Half-Life 3. Will they actually do it? Who knows! But it certainly feels like we're headed down a specific road somewhere in the future.