While upgrading to 2018c timezone, I found below changes :

./etc/localtime  ./etc/localtime    ==> Newly added

./etc/zoneinfo/localtime -> GMT ==> This entry is removed

./etc/zoneinfo/GMT  ./etc/zoneinfo/GMT  ==> Changed to ==> ./etc/zoneinfo/GMT link ./etc/localtime

./etc/zoneinfo/US/Pacific-New -> ../America/Los_Angeles  ==>  This entry is removed

./etc/zoneinfo/Africa/Sao_Tome -> ../Atlantic/St_Helena   ==> Changed to 

  ==>  ./etc/zoneinfo/Africa/Sao_Tome  ./etc/zoneinfo/Africa/Sao_Tome

Please let me know, if the above changes are expected according to 2018c  TZ database change.

Regards,

D Pal