Teradata made the decision to discontinue Kylo in early 2019. Teradata had been the sole sponsor of the open-source project and offered paid corporate training, consulting services, and enterprise subscriptions for support. The team was unable to immediately secure a new sponsor and devs have moved on to other projects.
The last official release of Kylo was March 2019. The downloads of the RPM and sandbox are no longer available but you may still build the RPM (or TAR) from maven.