Huawei Nova 5T is receiving the March 2020 security update with EMUI 10.0.0.197 and 155MB software package size (via Huawei Central).
Huawei Nova 5T users still receiving EMUI 10 around the globe and its users in Japan and New Zealand recently upgraded to this latest version of EMUI with added new features.
EMUI 10.0/EMUI 10.1 and Magic UI 3.0/Magic UI 3.1 April 2020 Update List: EMUI 10.1 beta timeline
For the users of Huawei Nova 5T, already upgraded to EMUI 10, now receiving a new software update with security patch improvement released in March 2020.
The March 2020 security update for Huawei Nova 5T includes Google security patches, fixing 2 critical and 20 high levels of Common Vulnerabilities and Exposures (CVE).
Note: The update is rolling out in batches so it may take some time/days to reach your device/country.