You are right. I was looking it up.
It’s really happening. The StarCraft II: Wings of Liberty campaign, ranked multiplayer ladder, and Co-Op Commanders will soon be available for everyone for free.
news.blizzard.com
Lmao, the news is already 5 years old.
Now keep in mind. Wings of Liberty isn't just an one-third Terran only preview. Wings of Liberty was the entire full product that was first released for SC2. Because few years before the release, Blizz wanted to milk their investment so they said, "we gon make 3 full titles instead of one Starcraft 2". I don't blame them as that's when Live service games and microtransactions were on the rise in the industry.
WoL has 30~ missions and 40 hours of gameplay.
The Wings of Liberty is the true SC2 experience as one would've had when SC2 was first released. You get to also control Zerg and Protoss a lot, you don't just play Terran the whole time. They mix it up well. You'll even play Zeratul's vision where you control a full Protoss base with carriers and motherships and the whole works against the almighty Xel'Naga.
It's a full SC2 product. Go enjoy it my friend.
Few years later they released another full 40 hour Zerg, then took another few years for the Protoss.