We have a custom app that was built using version 4.30 and includes the Print Widget. The widget was configured to only allow the UK A4 and A3 paper sizes via the following code:
printServiceUrl:
"https://utility.arcgisonline.com/arcgis/rest/services/Utilities/PrintingTools/GPServer/Export Web Map Task",
allowedFormats: ["jpg","png32"],
allowedLayouts: ["a4-landscape", "a4-portrait","a3-landscape", "a3-portrait" ]
Since the upgrade to 4.31, the print widget now shows the two Letter and Tabloid paper sizes.
This isn't a problem with our custom app, because the exact same behaviour can be replicated in the Esri sandbox: https://developers.arcgis.com/javascript/latest/sample-code/sandbox/?sample=widgets-print
