I think I can help answer that question for @jmorris. It's definitely something we're working hard to get up and running. We've made a number of significant internal changes to the SDK over the last couple of months to make it compatible with .Net Core.
Unfortunately, there are a lot of changes involved. In particular, there are a lot of places where the synchronous APIs have been discarded by Microsoft, so we need to refactor to use asynchronous API calls instead. Additionally, some of the dependencies, such as Common.Logging, haven't been fully updated with .Net Core support yet. So we have to either remove these dependencies or wait for them to be updated.
You can see some of the progress here: https://issues.couchbase.com/browse/NCBC-915. There certainly might be more subtasks added to this, we keep finding new issues as we progress. However, overall I think we're definitely making headway.