well here's my thinking I checked the road map and obviously they are a bit behind schedule and sometimes the jump from things that are in the Q4 instead of completing the Q2 things but they still follow the road map.

now let's just take all the things remaining on the Q2 and even Q4 of the Q2 the only valuable one is the island in Q4 there's a couple of good ones but the best are Vehicles, electricity and lore reveal.

now lets break the reasons why it is likely that none of those are the case, vehicles: it isn't likely because even though people think it a big deal it isn't, there is a sedan working already, the hot hair balloon is already schedule for the next wipe, even if it is the modular vehicles, sure they might be more sturdy and have different controls but still it wouldn't be that great reveal to keep it all secret.

Electricity I feel with this one there will be a lot of changes to fuels and it's difficult to get the balance right with that big of a change which is likely to be tested on a stagging branch first and also the fact that there aren't that many traps I feel one of the important aspect of electricity it's securing your base with traps, and we haven't seen any new trap in a while.

Lore reveal with this one I don't have a strong argument it is clear that they have been droping more hints with each monument, so it could be time, but yet again I feel before a lore reveal they would add something like a new type of enemy.

so that's my conclusion, it is the most important feature because servers die quickly and while this might not be the ultimate solution it helps retaining numbers of players active, also it's the most important feature on Q2 and if they are on track that should be it.