2020 Arch has 6 daily special left, here is what is missing from beta
Sok, WF selection kit, Victory Tower Upgrade, Wishing Well upgrade (note, there were 2 of these in beta but no Wishing Well), Checkmate Square, Balloon Site, Reno kit.
Here is the guesses with some confidence with explanation
1/6 my first guess will be 1 regular WW - 2 WW shrinks in beta, no regular WW. I just don't see them not offering a regular WW. I can see them offering WW shrink before regular WW but it is a regular offering, every event
2/6 Reno kit - another regular offering every event
3/6 Sok - over a year of data, same beta/live Sok
4/6 VT up - again very consistent over a years look. One time, 2019 Forge, they did 2 VT ups in beta, VT and VT up in live, but 2 of each
The real guesses
5/6 WF selection kit I can see dropping one WF selection kit, but I have mentioned, there is strong evidence they keep those types of offerings the same, beta vs live
6/6 So, Balloon versus Checkmate
Scenario 1, Checkmate dropped - It just may be too powerful of a daily special to offer. I know, huge player disappointment but there are no guarantees with beta offerings
Scenario 2, Balloon dropped - Maybe offer checkmate the last day, the day we usually have very little to spend. Make it a risk/reward deal. If you like gambling and save all scrolls for the last day, then you can win big if checkmate is offered. You will find completing the tablets hard due to time constraints, 4 hr productions (hello using those 2 hr supply rushes). The conservative approach, let's call it the Nickel slot machine player, take the carousels offered today, see what happens with special the next few days, maybe that last day possibility happens and you get 1 OR spend diamonds for more.
The main decision - Carousel offered today which I believe will be the last one (strong confidence on this one and supporting data). If you have no carousels, this may be the smart move, it is a good building (Age will also play a factor ie Iron Age player, do it for sure). If you stacked your inventory with carousels form last years event, like I did, you could always sell them in the AD, will be trade coin to get Checkmate in Auction.