the current version is "Update 2.3.67.3(A) (22 March 2017)"
what is the estimate when BG:EE v2.5 becomes available on the gog?

Beamdog has only released v2.5 for Icewind Dale. According to their latest update, they sent the v2.5 build to GOG last week, so we should be getting IWD 2.5 as soon as GOG finishes packaging and testing it.

Baldur's Gate I and II v2.5 are still in beta testing, with no estimate on their final release date yet. There will be at least one more round of beta testing before those games are ready.

oh, thank you! i thought that it already in the release state!

It would be nice, if GOG would offer the option to install the beta update. It's available on Steam and the Beamdog Installer for months now. GOG Galaxy does offer a Beta Channel, doesn't it?

please answer, what is the status of the beta channel?

GOG doesn't offer any of the Enhanced Edition betas -- either through Galaxy or otherwise. No idea why.

Just bought the $15 special deal for BGEE, BG2EE, SOD that expires in a day. In GOG Galaxy it is version 2.3.67.3 (B).
What does the B mean?
Under Settings in Galaxy to the right of the screen it says Beta Channels ON (I switched to ON when it was OFF).
Does Beta Channels ON mean I am playing the Beta version?
When 2.5 is finally released will I get that or do I have to switch over to Beamdog and buy the game from them after I already bought it at GOG? https://www.gog.com/promo/20180604_summer_2018_baldurs_bundle

Notice the pictures say Enhanced Edition.

No you will not have to buy it again (ofcourse). You will be able to update to the last version either through Galaxy or via a patch file that you can download from the game's page.

What Ryan emphasized is the "betas", not the enhanced versions. I do not have full knowledge about that subject but GOG usually does not offer "beta" versions of updates. I am currently on Linux so I can not open and check Galaxy.

So what does that mean "Beta Channels" ON vs. OFF?

A means Galaxy installer
B means non-Galaxy installer

What is a non-Galaxy installer? For example right now Baldur's Gate EE is (B) and Baldur's Gate 2 EE is (A).

Beta channel has nothing to do with the 2.5 Beta Update. Beta Channels are things being tested in the Galaxy program you can opt in or leave it OFF.

For a period of time, there were 2 kinds of installers. 1 was a normal game installer and the other one was with GALAXY included. It was automatically installing GALAXY when you are trying to install the game. This is no longer the case.

BTW, I am not sure about what A and B stands for. For example, BG2:EE installers are 2.3.67.3(A) yet they are Offline installers, AKA non-galaxy installers.

You do not need to worry about those if you ask me. Just install the game via Galaxy and update it to 2.5 when it is available through Galaxy.

I am guessing the A is a Galaxy installer and B is non-Galaxy installer. The non-Galaxy installer (B) gives only the 1.32064 version and not the 2.3.67.3 version (A)

Public Beta is working improvements for the Galaxy Installer with its features; whereas Beta Channels is actual game updates if the game update is listed. If it just says Yes or No then it is not using a game update. If you were downloading the 2.5 Beta update, it would give the number after the download.

If a person wants to download just files to play offline from the Downloads page they can do that, but that option is not listed in Galaxy.

So, 2.5 patch has been released. When it will be in GOG?

Quote from beamdog:
If you don't see the BGII:EE 2.5 update, please be patient as some platforms are slower to update than others.

Source:
http://blog.beamdog.com/2018/06/baldurs-gate-ii-enhanced-edition-25.html

2.5 Patch stiil not released for DL by GOG ?

Are you talking about the 2.5 patch for BGII:EE? If so, it's been available for download here for about three weeks now.