A lot is going on. Scion Linux is moving to OSDN and leaving SourceForge because of recent issues with downtime.
The next release of 18.3, codenamed "Venus", is due out in the next couple of weeks. With the change to a different installer, there have been some complications. Things are running a little behind as well because of kernel patches and the associated issues that came with them. The installer must work perfectly, therefore, the release will not be rushed until it is ready.
Venus is to be the first stable release after coming out of testing/beta. The only further updates afterwards will be through regular updates. I expect there may be a final version 18.4 which would be the last version of Scion Linux based on Ubuntu 16.04 LTS. However, I don't see this download as something necessary for someone who already has a previous version installed. It would merely be a package update rollup.
Once Venus is released, building and testing will begin to run a new version based on Ubuntu 18.04 LTS. News regarding the opt-in/out data collection hasn't bothered me very much, but seems to bother many. It hasn't been decided yet which direction Ubuntu will take on the default setting, but Scion Linux will definitely be an "opt-out" by default setting, meaning that if you wish to participate in the data collection, you must explicitly change your settings to reflect it.