Hi @prathees ,
What do you mean "wouldn't be getting 'PowerBIIntegration' functionality"?
If you means that you can not get the automatically generated app by choose "create new", then that does not mean 'PowerBIIntegration' become invalid.
Choosing "choose app" need you to customize app on your own.
You still could use PowerBIIntegration object in this way.
PowerBIIntegration object is not a functionality. It is a read-only data source in the embed app.
After you choose "choose app", edit the app.
In this embed app, you could use PowerBIIntegration object like this:
First(PowerBIIntegration.Data).fieldname

To sum up, if you want to get automatically generated app, choose "create new", in this situation, you can not customize screen size.
If you want to customize screen size, you need to click "choose app", then you will get existing app , not the automatically generated app.You could use First(PowerBIIntegration.Data).fieldname to get data of the powerbi report.
Here's a blog about this in details for your reference:
https://powerapps.microsoft.com/en-us/blog/powerbi-powerapps-visual/
Best regards,