Hello fikaso,
I knew when reading through the documentation it wouldnt make sense for Apple to abandon the command line tool as the GUI needs to have some programic way of communicating with App Store Connect whether that be the ITMS tool or altool. I havent found another way of uploading IPA files yet, but altool is still included with Xcode 11 and can be found by going to the below path.
/Applications/Xcode.app/Contents/SharedFrameworks/ContentDeliveryServices.framework/Versions/A/Frameworks/AppStoreService.framework/Versions/A/Support/altool
The one odd thing that I will point out though is that much of the Apple documentation has not been updated and most likely wont be which I have found to be a common thread amongst Apple support documents where they give just enough information but dont answer exact questions.
The version of altool that is shipping now is version 4.00.1181 which is the same that was shipped with the Xcode 11 Beta versions.
Hopefully this helps!