The website iPhone Soft states that the list for iPhones supporting iOS 13 may be losing two members. From the title you can determine the losers this round will be the iPhone SE and iPhone 6/6 Plus.
This is a change from last years list for iOS 12 that kept the same supported list from iOS 11. While iOS 12 did not have a huge list of brand new features it added refinement.
For me the iPhone 6 does make sense with being dropped as an older device on the list. Though the iPhone SE does not as it has the same A9 chip as the 6s/6s Plus. Beside CPU specs it would remove all 4″ iPhones from the line up.
From iPhone Soft here is the list of devices supported in iOS 13.
IPhone compatible with iOS 13:
iPhone XI and iPhone XIR
iPhone XS Max
iPhone 8 Plus
iPhone 7 Plus
iPhone 6S Plus
IPhone not compatible with iOS 13:
iPhone 6 Plus
Do not forget the iPad will be getting support as well, but also devices will be dropped as well. Here is their lineup.
iPads compatible with iOS 13
iPad Pro 12.9 inches 2016 and 2017
iPad Pro 10.5 inches 9.7 inch
iPad Pro 11 inch 2018
iPad Air 2
iPad Air 3
iPad Mini 4
iPad Mini 3
iPads not compatible with iOS 13
iPad Mini 2
Though as rumors go we will see what the truth is next month when Apple begins WWDC with the keynote making the announcement.