We strongly recommend that Geneious users DO NOT upgrade to macOS Catalina beta.
The next macOS release, macOS Catalina (10.15), is slated for release in the Northern hemisphere fall (Late September, 2019).
Apple have recently made the macOS Catalina beta release available to users as part of their beta software program.
Older versions of Geneious and the current supported version of Geneious (Geneious Prime 2019.2) have not been fully tested on macOS Catalina beta, and may not function correctly. In particular, Geneious cannot be activated on Catalina using a personal license (all versions), due to an issue with the Flexnet licensing component. An update for Geneious Prime 2019 will be released to address this issue.
Apple notes that macOS Catalina is beta software, and as such, "has not yet been commercially released by Apple, it may contain errors or inaccuracies and may not function as well as commercially released software."