For now you can either open the Keyboard Shorcut dialog and see if you can find your shortcuts in the Keyboard Layout Preset.
If that won´t work, use Finder to find the *.kys file and move it manually to the folder that looks like this on Windows: C:\Users\UserName\Documents\Adobe\Premiere Pro\13.0\Profile-UserName\Win (Not sure yet about the Mac equivalent.)
If i remember correctly when i upgrade i got a dialog that asked me if i wanted to transfer the Preferences from CC 2018 to CC 2019 and when i did everything worked as expected and i could use my shortcuts. It was the first time i saw this happen.