I was trying to find this information online, do the personal use license entitle the user to have the appstudio standard license? If yes, kindly share resource. If no, does this mean they will definitely need the ArcGIS Developer Subscription of Builder level or higher to utilize with the personal use license?
No, AppStudio Standard is not included with an ArcGIS Personal Use License. Correct, you will need to purchase an ArcGIS Developer Subscription of Builder level or higher to get an AppStudio Standard License.