Does this mean we cannot unlock all champs either yet ?
All 8 of our heroes are unlockable!
You can check out the link pinned to the subreddit but to give you an overview, this is what you get for joining Early Access (copypasta incoming):
Eight unlockable characters each with unique play styles
AFK-proof combat and challenging battles versus mobs, elites, and despicable bosses
WASD controls so you can take the wheel and deploy precise tactics on the battlefield
Three levels of difficulty – if "normal" doesn’t scratch your itch
Compelling story campaign of five acts, inspired by Slavic myths
"Legacy Point" progression system - unlock all eight heroes to get access to the biggest and baddest challenges (and rewards!)
Satisfying crafting system which lets you forge the weapon that is just right for you
The Pantheon – your new home, a place to meet and show off Emotes and skins for each hero – make a statement
Game modes galore! Threats, Missions, Hunts, Assassinations
An Early Access exclusive companion pet – Archmage Woodward – who gives a 7% gold bonus!
Hope that clears it up.