1729 has hit the nail on the head about Platform. It's a maze which stands all year around, bar the tunnel which I imagine can be set up in a day. Yes, they've done little tweaks to it (and big tweaks in 2017), but once built they can pretty much just leave it as is and just doing a yearly maintenance check on it. It's certainly not the best received maze ever, even in its best, 2017 state, but it does the job. It also had an expense initial outlay, so they'll use it for what it's worth.
However, I have heard murmurs that the village section in the maze has been torn down. If true, that indicates that some more substantial work is happening. It doesn't surprise me, as I was under the impression that the creative team behind the maze at the time (who have since moved on, etc) it was built had bigger plans for the maze and intended to keep growing it, and the village was more a short term thing which was built to last several years. So maybe it's needed the work.
Obviously, all Chinese whispers and murmurs, but take it for what you will.
Also, whilst I don't think there's much to go on, it has been noted that there have been removed trees around the Loggers / Platform route. It could mean nothing. But if it is happening for a future development (or something else, like the trees round that are at risk of being unsafe), then maybe the park don't want to spend money reinvigorating / changing Platform too much only for it to close down shortly thereafter.
This is the overarching problem Fright Nights has had though for a while. Ideally, they need mazes permanently set up (a la Creek Freak, and in the past, Saw, Living Nightmare/Cabin, Asylum, etc) which can survive the elements. Things like Platform 15 and Roots of Evil (curiously not listed as returning)/Blair Witch are obviously permanently set up, but struggle under the elements and need more maintenance. Even something like Experiment 10/MBV were good as they were at least straightforward to set up. The issue with mazes in tents is that you either have to have a tech crew who can build them from scratch (whilst also doing everything else, and prepping the other mazes), or get an external company to do it all (which is expensively, especially if done yearly).
Realistically, I feel like for this year's Fright Nights we can expect the Jungle Escape building to be transformed to a maze, maybe a Roots of Evil replacement and some scare zones.
-The Jungle Escape building is a prime location for a maze, and it will help majorly with set up to have another indoor permanent maze.
-Roots of Evil was a bit meh and the location can only do so much. 2018 was a logistical nightmare with Vulcan Peak and Blair Witch, so maybe they'll avoid 2 mazes there.
-Scare zones were good and successful last year, so they need to return.
I do wonder how much Covid has affected plans for this year. Despite the size of the park, I imagine they would still be hesitant to commit to big money spending for something which may not come to light / be disrupted. But equally, leave the decision too late and you then have to rush stuff / can't get the right people in. It's difficult.
I'm surprised the park didn't decide to delay the 20th anniversary in some sense. In the grand scheme of things, it means very little, but enthusiasts and the park's marketing team have pushed it a lot and expect an extra layer of something special. Maybe they could have said "Last year was the Fright Nights Fearstival, not Fright Nights itself. So this year is the 19th Fright Nights and so next year is the 20th edition, blah blah blah...". That way, they could look at committing to a more secure world (or at least, more adjusted world) and more secure event, where they could spend more money. But heyho, it is what it is.