You will have to select from the drop down box a LCD display , your exsisting display won't communicate with the KT so one will get error code and a non working bike.
The motor connector is good but as has been said one may need to change a Hall or phase wire sequence so if possible one will need a controller that uses non water proof connectors, otherwise one can't change the sequence.
The motor though is a Bafang and my one works perfectly without any wire sequence change , likely hood is it will work unless Gtech spec'd ones are wired differently.