Yes it's 10TB.

I nearly hit the cap once when I first testing sunshine/moonlight to see how much bandwidth my set up could do and kinda FOMO for the steam deck hype.

It's like 150 mb/s and works so well (for the kind of games I play) that I forgot the egress cap and just play for like a weeks even in the house, I realized and stop at ~ 9TB. My usual usage don't even hit a TB most of the time lol.