The changelog on Outcast works just fine here.

Huh? The changelog is always present. I can view the changelog of any game in my library that has a changelog at any time no matter if I have or have not read it already.

Are you using Galaxy or the website to access your account?

Try refreshing your account, for I see the changelogs of all three (regardless of flag status). If it doesn't work, open a ticket.

Meanwhile, you can always examine their changelogs on MaGog (just search for the specific title and look under "Downloadable Files", or simply use the links below):

Outcast: http://www.an-ovel.com/downloads/chg/chg_1207658853.htm
Legend of Grimrock: http://www.an-ovel.com/downloads/chg/chg_1207659016.htm
Broken Age: http://www.an-ovel.com/downloads/chg/chg_1207662943.htm

P.S. I still cannot understand why GOG insists on making changelogs available only to game owners

From MaGog's logs for 23 July:

NOTE! CHANGED Kyn - Standard Edition Preorder [Upcoming], rls_date: Unknown ***TO*** July 28, 2015

[The deluxe edition already had the date listed for a while now]





NOTE! CHANGED Odallus: The Dark Call, file_size: 131 MB ***TO*** 132 MB

[I don't own this game, so MaGog will not be able to report about file changes]





NOTE! CHANGED Victor Vran [Upcoming], os: Windows (XP, Vista, 7, 8) and Mac OS X (10.9.0 or newer) and Linux (Ubuntu 14.04, Mint 17) ***TO*** Windows (XP, Vista, 7, 8) and Mac OS X (10.9.0 or newer)

NOTE! CHANGED Victor Vran [Upcoming], sys_req_linux: Ubuntu 14.04, Mint 17, Processor: 2 GHz Dual Core CPU, Memory: 4 GB RAM, Graphics: OpenGL 4.1 (GeForce 600 or higher, AMD Radeon 5000 or higher, Intel HD 4000 or higher), Hard Drive: 4 GB available space, Recommended system requirements: Ubuntu 14.04, Mint 17, Processor: 2.5 GHz Quad Core CPU, Memory: 4 GB RAM, Graphics: OpenGL 4.1 (GeForce 660 or higher, AMD Radeon 7000 or higher), Hard Drive: 4 GB available space ***TO***

[So, no linux version, at least initially?]

I guess that implementing a public changelog feature (and by public I don't mean forums), might end up breaking something else in the site.

There is one. See post 9759.

Umm, that's public if you know where to look. Same case as including it in a game's subforum (which have an unfortunate tendency of being a graveyard for some not-so-famous games). ;)
Preferably, I would want the public changelog to be accessible from a game's page, in a way similar to Steam's product updates/related news page. Of course, on Steam the developers/publishers are responsible for the content of a game's page, so I'm not sure how efficiently could GOG do it.

Do you mean "always, as long as you can see the notification about updates" or "always always"?

Always always. May need to be made first, but viewing the changelog doesn't need an update notification.

"Always always".

Always always ;-)
I just checked it and I can see the changelogs of games that no longer have the notification and where I downloaded the update some weeks ago.

To further clarify all the answers above, "always always", assuming the game has a changelog (games that haven't changed in the last few months usually don't have one).