eiii: With the difference that in other parts of the site I do not have to use the filter and can see all entries when I do not use it. And in the opposite to the chat page the other filters are not in my way. [...]
I'm just telling you how it works, not that it necessarily works better from a user PoV.
On a side note, you couldn't see
all entries (contacts) with the previous version of chat either. The contact list was limited to 200 users, and every user that clicked on your "Start conversation" got themself on your list, kicking off an existing one from the bottom of your list.
eiii: [...] I do not see any reason why that couldn't have been done with one user list and requires two user lists now. But I do not use the GOG chat too often, so I also can live with this more complicated mechanism.
I'm not privy to more info, but here's what I think.
The so called "suggestion list" is ordered from newest to oldest communication*, with the seven most recent being immediately visible, if you don't have any unread messages. The search/filter box can practically be used to bring up any registered user, whether you've chatted them before or not - at least that was my experience from a little bit of testing.
The permanent contacts lists in the previous chat version had two major shortcomings:
(1) Any user could add themself on it, without even having to utter a single word to you.
(2) It was limited to 200 users, and with point (1) being in play, you could easily end up with a pretty useless list, or at least a bloated one with people you didn't know or cared to communicate privately with, while people you wanted would fall off, and you'd have to add them back by clicking on their "Start conversation" on the forum.
Since the current chat version has been live in the client for quite some time now, it's also possible that the old one didn't work all that well in it, or was used more in the way GOG intended from the beginning (see next paragraph), hence the change.
GOG moved away from the more traditional, if you want, private communication that was the old PM system, to a more_like_an_IM system with chat, i.e. "chat now, chat briefly, move on", when the NAS rolled out; it's been my impression ever since that this is the way the chat's intended to be used, and I don't think I'm wrong. The redesign makes this more prominent, and at the same way (i.e. ditching the previous one) solved the above mentioned issues, possibly others too. And that's it.
Regarding the suggestion list - a better, imo, implementation would be to make it collapsible, and start it collapsed when one opens their chat without having unread messages, or triggered to pop-up when clicking the plus sign. I don't know how difficult that'd be, but eiii is right that it's too much in your face, more so with so much blank space around it, plus, it's not immediately apparent who and why is on that list, and what purpose it serves.
* Sorry, but in typical GOG tradition, that suggestion list and the order of users on it is anything but reliable. Scrolling through it revealed that people I hadn't exchanged a word in years are listed (even WWTDead, one of the very early alt accounts of scammer wakalo from back in late 2013, for crying out loud), while others I've had exchanges with in a lot more recent times are prominently missing (when they were present in my contacts list of the old chat).
And I'm not sure if all the messages exchanged with each user are still here. That is the ones made after the NAS was introduced, and those that survived the transition from the old PM system. The rest have been purged for good, in spite GOG saying for months after the NAS was rolled out that they'll look into restoring them.