I think in terms of predictions, my main worry would be something like the chain that led to 4e. Here's what went down with that:
- 3e launches in 2000 and sells incredibly well. Star Wars d20, also released that year, is also a huge sales hit.
- By the end of 2001, sales have trailed off. Work on 3.5 starts in early 2002 or so.
- 3.5 releases in 2003. The changes to the game are kind of random and rushed, and are designed to make the D&D collectible miniatures line an integral part of the game.
- The minis sell well, but D&D book sales slump back down after a brief spike. Initial concepts for 4e begin in 2004, driven by a pitch to shift D&D to a digital platform similar to World of Warcraft. The game enters full design in 2005, with a target release of 2008. The game's design is driven by MMO-style play and a reliance on miniatures.
- Meanwhile, D&D miniatures costs start to go up and sales start to go down. During the same period, many companies launch MMOs to compete with WoW, but none come close to matching its success.
- D&D 4e launches in 2008, sells great for a 3 to 6 month window, then craters.
Fundamentally, 4e failed because all of the plans around it were based on two things that proved wrong:
- The core game play of WoW was portable to other games. It wasn't.
- D&D miniatures were a sustainable, growing business. They weren't.
When a business becomes shaky or is shrinking, there is pressure to deliver a perfect, long-term plan immediately. That pushes you to overly rely on current trends and extrapolate them forward, rather than engaging in deep R&D to figure out a durable solution.
Part of 5e's success came from rebuilding the team's R&D capabilities. It's easy to forget, but in the years before 5e launched the D&D team won the Origins Award for best board game three years in a row. That patience paid off with 5e.
All of this is to say that what happens next depends on whether 5.5 is hitting its sales mark, and what that prompts Hasbro to do. My biggest worry is that there's a knee jerk reaction toward moving ahead with a radically different game design. If they perceive 5e as a dead end, they'll be under huge pressure to do something completely different.
All we can do is read the tea leaves, but seeing them go back to a product each month starting in July is not a good sign. It feels like something a team is told to do to make up for a budget shortfall. Do you have faith, given the rules issues in the 5.5 rulebooks, that giving the team less time to make mechanics is going to lead to higher quality products?