Hello @Jiří26444344jv88,
Thanks for reaching out. Illustrator does not natively have this functionality. You may, however, save the master template as a separate Ai file and then include it in your files as a linked file. This way, whenever you change the master template, it will automatically update the linked files.
Alternatively, you can use the Parent Pages feature in InDesign (https://adobe.ly/4cK6RGv).
Feel free to reach out if you have more questions or need assistance. We'd be happy to help.
Thanks,
Anubhav