Looks like we're headed into two more sales for this year; Black Friday and Winter/Christmas/New Years.
Reminder about GOGdb, to check historical lows and whatnot for optimal bang for yer buck during sales.

Depends on your definition. I wouldn't count this sale as any more than a named Weekly sale. Less than 100 titles in the sale.

1) Probably still be a pre-Turkey/Black Friday Fall Sale which probably will start next week.
2) Expect a Black Friday sale. If we have a sizable Fall Sale then this might be more of a slightly larger Weekend Sale.
3) Then the Winter Sale which will be before Christmas and be the biggest of the bunch. Starting 1st or 2nd week of December.
4) Then a Holiday/New Years sale. Again, probably a slightly larger Weekend sale.

Considering that there's also a Polish Developer Sale taking place on STEAM, maybe this is the hallmark for another recurring sale. I never realized there were so many high quality Polish made games, but it's great that they are so proud about their work, that they've created a seasonal sale to inform everybody about it. Keep it up Poland!
Nice prediction, but it feels kind of cluttered. I'd expect only a Thanksgiving sale(probably Piñata styled), Winter Sale, and a smaller weekly&weekend sized sale for New Year's.

We've only had one BIG sale this year, Summer Sale (almost 1700 titles). Some medium-sized sales (500-ish titles) like Chinese New Year, St. Patrick's Day and Back to School, although the latter had a lot of titles, it was very weak on special discounts. If the plan is to have 3 BIG sales, one almost has to be next week not to crowd the Winter sale too much.

Last year was the first time in quite awhile GoG didn't have a "Big Fall Sale" of some sort to go with the Winter Sale, unless they've given up that idea. The Big Deal Sale wasn't that big a deal. We should have a good idea next week.

It seems GOGdb can't download prices from GOG since beginning of November.

Yes but during Weekly sales we also have Daily Deals but not with this one - so we cannot count this sale as another Weekly sale.

Edit: Looks like GOG does count it as Weekly Sale but it's weird there are no Daily Deals.

The definition this thread seems to use is that the sale has a special whole page theme going on.
Seeing as Halloween wasn't really an event sale, more of a weekly, I'm hoping for a Black Friday/Cyber Monday big sale before the Winter one.

Also would help if my wishlisted games come on sale lol.

Next week is Steam Autumn Sale - GOG sale is planned when?

On Monday, obviously! ;)

Are you sure ?

Of course not. But if there is to be one, and it has to hit before STEAM starts theirs, Monday is the last day it could start. STEAM's Autumn sale will start on Wednesday.

Does it really need to be before steams? Could it be later than steams?

GOG has always started before STEAM sales. One can assume that there's a marketing tactic about that. Probably people would be more tempted getting a game now on sale, wherever that sale might be, than waiting a week or more for a STEAM sale.

And people who bought it on one platform aren`t likely to buy it a second time on another. So, GoG starts before STEAM, so the people buy here. If STEAM starts earlier, they maybe have spent all their money there, so there`s no money left for GoG.