I think it's worth pointing out that Survival Games ended up costing more than Trailers. And Creek Freak Massacre was, at the time, the park's single highest investment for a maze and lasted 3 seasons. So high cost doesn't mean it has to be around for a long time, although I understand the point and broadly don't disagree.
I've seen people on social media talking about how Trailers in particular is "old". It's a very interesting discussion point. It's had 4 seasons now, and last year was the first year we saw substantial changes to it (though arguably, those changes weren't really substantial, just a redress), and is the oldest in the line up.
But in the past, the park had mazes last for several seasons...
Asylum - 9 seasons
Saw Alive - 9 seasons
Se7en - 6 seasons
Hellgate - 6 seasons
And there's even more recent examples of mazes lasting a few years...
Platform 15 - 6 seasons
Blair Witch - 6 seasons (with a brief gap)
The Curse - 5 seasons
Containment - 5 seasons
Obviously the glaring difference right now is the fact the mazes are upcharge. But then, plenty of places keep mazes for a long time. Towers is a fine example. Lots of international parks (some of which have better Halloween events than Thorpe) do. And scream parks, some of which have mazes set up in situ all year round, have kept mazes for a long time (Tulleys has 5 mazes which are at least a decade old, have just retired one which was 15 years old, and have a couple which have been rethemed but are otherwise the same). My point is, keeping attractions the same for a long time isn't uncommon at other places either.
Thorpe certainly gets held to a high expectation with Fright Nights. And recently that's at least partially their own doing thanks to the high maze costs, and their own marketing hype. But at the same time, I don't think a maze potentially having a run of 5 seasons is that long or necessarily a bad thing.
It will be interesting to see what happens this year. The park have introduced a new maze every year since 2010 (if you include Saw Alive). Okay, there's a couple of loose definitions of new in that list but still. It's the expectation that there will be a new maze every year. In the same way in the past there was an expectation of a new ride every year.
But with changing budgets and a complete behind the scenes overhaul, plus this being the last year that Thorpe run Ents themselves, who knows what this means. But if they don't introduce a new maze, I'll be very interested to see how they market the event and where they place their focuses.