This is not a steam weekend update, however, Steam just started a promotion about 6 hours ago which includes Stellaris free to play for 5 days.
Steam has brought another two amazing games free to play for us and that during the weekdays. Stellaris and The Golf Club 2019 is free to play on the platform.
You can play Stellaris for the next 5 days and The Golf Club 2019 is free to play for two more days.
Also, there are two free to keep games on the platform that you can claim today. Showdown Bandit and Geneshift: Wahe GuruBattle Royale Turbo are the two free to keep.
Offer to claim Showdown Bandit will expire in 5 days, but with Geneshift: Battle Royale Turbo you need to hurry up a bit since it is available only till tomorrow.