Currently TZUpdater doesn't support vanguard format tzdata which the tool directly consumes from IANA site: https://www.iana.org/time-zones/repository/tzdata-latest.tar.gz
This is because of the negative DST save value and Japan zone rule where hour is expressed in 25:00 format, which are not compatible with the current version of the tool.
Please refer to https://bugs.openjdk.java.net/browse/JDK-8212970
for more information and to see the fix made into JDK for this issue.
The similar fix needs to be made into the TZUpdater tool as well.
Since the tool is used by many users and customers, we are planning a temporary fix to the tool, which will convert the non-compatible vanguard tzdata into compatible rearguard tzdata before it is processed by the tool.
This is similar to what the IANA script does here: https://github.com/eggert/tz/blob/master/ziguard.awk