I want to upgrade my phone to an iPhone 15 and use my iPhone 13 for my drone monitor.  Does my Mini 2 monitor need to be receiving mobile account service?

Hi, A Filipino Life. Thank you for reaching out. Do you mean the mobile data? If yes, you don't need Mobile Data Services when flying the drone. The only times you'll need it to be connected to the internet are the following:
1. Log in and log out App account
2. Sync flight record
3. Use the Academy function
4. View the app's map √ (Internet connection required for first-time use)
5. Download the offline map
6. Firmware update

Hope this helps.