• Divinity: Original Sin 2 - Sir Lora – from $2.99 to $0.0 (-100%)

• Port Royale 4 - Extended Edition – from $54.99 to $44.99 (-18%)
• Tropico 6 El Prez Edition – from $54.99 to $44.99 (-18%)
• Port Royale 4 – from $49.99 to $39.99 (-20%)
• Tropico 6 – from $49.99 to $39.99 (-20%)
• Immortal Realms: Vampire Wars – from $39.99 to $29.99 (-25%)
• Shadows: Awakening – from $39.99 to $29.99 (-25%)
• Shadows: Heretic Kingdoms – from $39.99 to $29.99 (-25%)
• Omerta: The Japanese Incentive – from $9.99 to $4.99 (-50%)

• Loria – from $9.99 to $0.0 (-100%)
;)

Fechtbuch: The Real Swordfighting behind Kingdom Come [Film] is free.

I am fairly certain it wasn't free last time I checked (February). I don't know when it became free, as I'm not aware of anyone monitoring GOG films.

• Sherlock Holmes: The Devil's Daughter – from $19.99 to $29.99 (+50%)
• GreedFall – from $49.99 to $34.99 (-30%)

• 1971 Project Helios – from $24.99 to $14.99 (-40%)

Heads up: https://nisamerica.com/blog/upcoming-changes-pc-games-pricing

Though Ys VIII has Stadia and Steam in parenthesis only, while The 25th Ward doesn't. So I have no idea what's going on there.

They already removed regional pricing from GOG.

• Expendable – from $5.99 to $3.99 (-33%)
• Mobile Forces – from $5.99 to $3.99 (-33%)
• Hostile Waters: Antaeus Rising – from $5.99 to $2.99 (-50%)
• Incoming + Incoming Forces – from $5.99 to $2.99 (-50%)
• Litil Divil – from $5.99 to $2.99 (-50%)
• Normality – from $5.99 to $2.99 (-50%)
• Nosferatu: Wrath of Malachi – from $5.99 to $2.99 (-50%)
• Realms of the Haunting – from $5.99 to $2.99 (-50%)
• Slipstream 5000 – from $5.99 to $2.99 (-50%)
• Soulbringer – from $5.99 to $2.99 (-50%)

Yay, finally!

Last week I decided to remind about this issue (the publisher lowered the prices of these games on Steam more than 3 years ago) in the weekly sale announcement topic, and it looks like it worked!

The publisher of these games was also changed from Blue Moon Red Owl to Funbox Media Limited (as on Steam), but as far as I know, Blue Moon Red Owl is the Funbox Media Limited subdivision for mobile games.

• Eagle Island – from $19.99 to $12.99 (-35%)

It seems you are right.
You can check this out here:
https://www.gogdb.org/product/1435294665

Yup.

• Metro Exodus - The Two Colonels – from $7.99 to $6.99 (-13%)
• Metro Exodus – from $39.99 to $29.99 (-25%)
• Metro Franchise Bundle – from $96.99 to $59.99 (-38%)
• Metro Exodus - Gold Edition – from $64.99 to $39.99 (-38%)
• Metro Exodus Expansion Pass – from $24.99 to $14.99 (-40%)
• Metro Exodus - Sam's Story – from $17.99 to $9.99 (-44%)

• A Plague Tale: Innocence – from $44.99 to $39.99 (-11%)