A noob with coming on four years experience.
Glad my name isn't four years experience
Crossposting is just getting started and likely going to get abused y some. However, for example if I find content I really want to reward as well as I can, I can crosspost it into a community and it will count as "my own" meaning it will get the benefit of my autos. However, 90% will go to the original author, 5% to me for the share, 5% to the community it is crossposted to. That incentivizes sharing beyond the curation mechanism for those who do have a following, but not a lot of SP.
For those who abuse it (I will likely say there will be a few large accounts crossposting their alt content to their own to doubledip), they will get flagged and hopefully lose their autovoters trust. That is a good thing too. I won't crosspost my own unless there is some very good reason to, but, I want people to know that if I do crosspost someone else's content, they can trust it is worthy of at least the rewards they would give me.
For those who are short of content, they can bump other people a lot and get them reward and exposure to new communities and eyes and still take a small slice for themselves as well as get some support for the communities they enjoy. The feature is evolving and there is a long way to go.