Would be nice for sure, I am in the same situation and felt a bit dumb on Wednesday.
There is a valid reason to have both applications on your IOS device as Go 12 will only open and run 12 and Go 1.x will only open and run 1.x.
Why should you have both? Because there are and always will be both file versions just as there are Filemaker Pro 7, 8, 9, 10, 11 and 12.
And newcomers buying 12 may have to BUY 1.x!
And, as I have pointed out, your solutions may have problems with 12 so your conversion should not be instaneous and total but over a period of time.
Filemaker Go 1.x is going to continue to be userful for quite some time since it is the version that will open all pre-12 files.
And, exactly how much has 1.x been used on a computer? How much useage can be rebated as unusued? Etc.
Don't delete or discount 1.x until your converted solutions have been debugged for the new error messages you are encountering because of lazy programming...