The difference is that to update, you'll need to download a new .deb file. If you want to use apt or apt-get to update edge, follow their instructions for the command line install at https://www.microsoftedgeinsider.com/en-us/download :
WARNING: I'm not sure if the code below will work without uninstalling edge first, so beware.
## Setup
curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.gpg
sudo install -o root -g root -m 644 microsoft.gpg /usr/share/keyrings/
sudo sh -c 'echo "deb [arch=amd64 signed-by=/usr/share/keyrings/microsoft.gpg] https://packages.microsoft.com/repos/edge stable main" > /etc/apt/sources.list.d/microsoft-edge-beta.list'
sudo rm microsoft.gpg
## Install
sudo apt update
sudo apt install microsoft-edge-beta