I thought that turned out not to be true? That by default it behaved like a joystick and mouse like the original steam controller?

It's wild because it isn't true

It does work as a mouse by default. Valve calls it "Lizard Mode", and you use the touchpad to move the cursor and the triggers to click.
But yeah I do agree they should have made standard buttons and sticks act as XInput and the touchpad as the mouse by default.

that being said, I fucking hate microsoft for stifling controller innovation with their antiquated ass xinput so i when i see a controller not support it i have to force myself to not think "god bless"

I can‘t speak about software updates just yet because I have only seen them being applied via Steam but the controller works out of the box. I‘m assuming you can update it by downloading a file too, though. That would put it far above some competitors because guess what? A lot of them let you install some shitty software for that. At least Steam is already installed on my machine. I run Linux after all and ironically Steam is already helping me setting up controllers from other manufacturers.