(In alphabetical order)

I've spent a lot of time adding details to titles on IGDB. Every yet-to-be-released 2020 and 2021 IGF entrant (from my other big lists) I could find is here. I did not include any Early Access games. Includes major port releases.

May-confirmed games:
Before We Leave (Steam release)
Flow Weaver
Highrisers
Hundred Days
Lacuna
Of Bird and Cage
Sherwood Extreme
Skate City (coming out of Apple Arcade exclusivity)
The Invisible Hand
Weaving Tides

Games not included in this list for arbitrary reasons:
A Space for the Unbound
Axiom Verge 2
Butterfly Soup 2
Cuphead DLC
Darkest Dungeon II
Earthblade
Essays on Empathy
Hollow Knight Silksong
Industries of Titan
Katana Zero DLC and sequel
Millennials Story
Oxenfree 2
Outer Wilds DLC
Pocket Squirrel
Project Sidereal
Skatebird
Solar Ash
The Glory Society's latest game
The Longest Road on Earth
The Stanley Parable Ultra Deluxe
Whisker Squadron
Many Switch ports
....and probably many, many others

Delisted games:
Cat Lady (developer has removed the game from early access, will release after their other titles Floppy Knights & Garden Story)
Wildbus (developer has confirmed no re-release; working on other games)
Night Terrors (website appears to suggest a re-release in the fall)