Big Top v1 was atrocious though, it has been much better in 2016/17 through leaving more time to get it built up and configured well - that and the fact it was pretty much an entirely different maze to the 2015 version.
I don't think the lack of any construction is too worrying at this stage, but leave it much longer and it means there's less time to build a decent quality attraction and a rush job is more likely.
Also, I don't personally find outdoor mazes to have the same appeal, so TBT swapped for Blair Witch (IF that is what's happening) would be very disappointing IMO.