I’m glad you like your predicted cabins. So far when a number has appeared with the barcode trick it has always accurately predicted my gty assignment. Of course, the cruiseline is allowed to change around gty cabins if they wish (though they rarely do), so I admit there’s an off chance one could change sometime. Also, while the apple wallet method seems fool-proof, barcode reading apps can be more finicky, so one needs to take care to really get a valid barcode reading.