'Half-Life Collection' May Go Free-to-Play Ahead of Half-Life: Alyx Release UPDATE

Half-Life: Alyx may prompt Valve to offer the entire Half-Life series to players for free, according to screenshots of a Steam client notification some players received Monday.
The notification, a picture of which is available here, tells players that a Half-Life: Alyx event has started, making the "Half-Life Collection now free to play until launch of Half-Life: Alyx!"
Clicking the notification brought users to an error page.
Valve did not return a request for comment.
Steam does not currently list a bundle titled the "Half-Life Collection." Close analogs include The Orange Box, which contains Half-Life 2, Episode 1, and Episode 2, and the Half-Life Complete bundle, which includes all eight Half-Life titles released by Valve. Neither bundle is free.
Valve revealed Half-Life: Alyx Nov. 21 with a gameplay trailer. It is Valve's first new Half-Life game since Half-Life 2: Episode Two, released in 2007, and its first foray into virtual reality game development.
Half-Life: Alyx is scheduled for release in March.
Update: The promotion has since gone live. Players can install all 13 games in the Half-Life franchise for free for the next two months.