Steps to reproduce:

Install the package zabbix-sql-scripts_7.0.0~alpha8....deb (ubuntu or debian). 
Take a look at the files in /usr/share/zabbix-sql-scripts/postgresql/timescaledb 
There is a file schema.sql in stead of timescaledb.sql

Result:
schema.sql file
Expected:
According to documentation, expect timescaledb.sql https://www.zabbix.com/documentation/devel/en/manual/appendix/install/timescaledb 

Installation from source (7.0.0beta1) provides timescaledb.sql

Change from timescaledb.sql to schema.sql is made in ZBX-23797