With the pike deaths from the fair being shown in the penultimate episode of season 9, The Walking Dead appears to have finally learned from its season 6 finale mistake. Before Alpha and the Whisperers entered the fold in The Walking Dead season 9, the series' big bad were the Saviors, who ruled over and terrorized all the communities for two full seasons. But it all began with The Walking Dead's season 6 finale.
Throughout the second half of season 6, The Walking Dead kept teasing and setting up Jeffrey Dean Morgan's Negan, who eventually showed up for the first time in the season 6 finale, "Last Day on Earth". In that episode, Negan and the Saviors gathered up The Walking Dead's main characters and lined them up. Negan then played "Eeny, Meeny, Miny, Moe" in order to select who was going to be killed. But the thing is, viewers didn't find out who died (despite hearing the person being killed) until the season 7 premiere. The season 6 finale cliffhanger was a mistake.
By holding off on showing who Negan killed, The Walking Dead suffered critically and commercially. While the season 7 premiere saw a sharp uptick in viewers, the average number of viewers throughout season 7 dropped, and the series hasn't recovered in the ratings ever since. However, with Angela Kang as the new showrunner, The Walking Dead's writers and producers learned from season 6's cliffhanger and didn't hold back on showing who the Whisperers killed during the fair until season 10.
First off, instead of teasing all the major deaths - or, at least the ones viewers were expecting to see - in the season finale and holding off on actually showing who died until the following season premiere, The Walking Dead revealed all of the fair/pike deaths in season 9. But more than that, all of the deaths were actually shown in the season's penultimate episode, "The Calm Before". By doing so, The Walking Dead took a page out of Game of Thrones' book by having the climax of the season take place prior to the season finale, so that there's still time to reflection and set up for the following season in the actual season finale.
In doing all of this, The Walking Dead learned from their mistake with the season 6 finale cliffhanger and retained audiences' interests by teasing an even bigger season 9 finale, simply by having viewers wonder what the aftermath will be. This way, fans don't have to wait more than six months to find out what comes next. Cliffhangers are difficult to nail down, and withholding a major event that has been teased for weeks - if not months - risks displeasing the fanbase.