The "steady state" is a part of what I'm talking about this the films as well. Audiences react differently to a series with 1 year gap, 3-4 year gap, or 10 year gap. Merchandise will follow, especially since those numbers
pre-date the film.
Star Wars toy sales doubled for 2014 (pre-TFA) to 2015 (TFA), so somewhere in-between the "no new Star Wars" and "Rogue One" in probably the middle ground.
The mental math is: TFA did $2 billion, but that's not sustainable per film unless they're A) spread out and B) always events. So, that puts that number out of the running. Rogue One and TLJ are $1 billion and $1.27 billion respectively. So, do you bet on a $2 billion film every few years, or a billion every year? Problem is, we don't know what the average float for Star Wars is. Maybe it's a billion. Maybe it's $900 million. We don't know.
Yeah, but that's not really a problem with Solo or a trend. I honestly don't think Solo would've ever be a billion+ film.