You can toggle on Zia's suggestions during manual record creation via the Zia tab (Setup > Automation > Assignment > Zia), as well as add the users that can be considered for suggestions.
The dashboard also has two new additions: Zia's suggested owner reports and Check Zia's suggested owners functionality.
Zia suggested owner reports
You can now view the records that Zia has assigned, as well as the subset of those records that have been manually reassigned. You can filter this view by duration and navigate to individual records from here. This helps you measure Zia's accuracy, identify reasons for high manual reassignment rates in a particular team, and so on.
Check Zia's suggested owners
You can check how Zia assigns users in the Zia tab. Using the newly added Check button, you can prompt Zia with values for the different factors that are contributing to record ownership. For that specific set of values, you'll be able to see the hierarchy of Zia's suggested users. You can also use this to check Zia's performance on individual or sets of factors.
These are available for Enterprise edition and above.