I talked to tech support and apparently, it's a bug in the Share widget. They created an enhancement for it to be able to accept two parameters at once (query and scale) rather than having one overrule the other the way it does now.
"ENH-000119500: Use of "Query feature" parameter with "scale level" parameter, or use of more than 2 URL parameters depending upon the desired functionality"
For now, my users will just have to make that second click on the Zoom to button after opening the app if they want to see the full extent of the feature.