This could be either site tools or popular Reddit bots that need to be ported over.
I think a big reason so many subs are going dark tomorrow is due in large part to how hard Reddit is about to make moderation - so it might make sense to make this an area of focus for Lemmy.
The #1 thing missing is user notes. In my experience, being able to attach notes to users that are shared among moderators is essential, even for smaller teams or smaller communities.
As the number of things that need to be moderated grows larger, being able to maintain a list of pre-written removal messages will also help a lot.
And as lemmy continues to grow, it will be very important to have something that works like automod that can be configured on either a per-instance or a per-community level. Especially something that can do filtering and auto-reporting. There are a lot of cases where you don’t want to outright forbid a certain kind of content, but you do always want to bring human attention to it.