Hi Hunter, the API level 26 is not a requirement due late 2018, see https://android-developers.googleblog.com/2017/12/improving-app-security-and-performance.html
When reverting back to API level 23, you will find that Play will just give you a warning.
For what I remember (not confirmed) you need to remove the crosswalk webview plugin in order to make it work for API level 26. To disable crosswalk you need to comment out the cordova-plugin-crosswalk-webview and com.crosswalk.cookies plugins
Can you disable the crosswalk plugin and tell us the results?