On my Lumia 930, I keep getting error 0x80073cf9 only on apps that weren't made specifically for W10. I've done a soft reset but that hasn't fixed anything.
I looked through the Feedback app and noticed a lot of people have gotten this bug but what's weird is I've had hit or miss app updates since I started using the preview with build 10166.
Yupp on the hit or miss thing My phone is currently out of commission, but when I get it back, I'm pretty sure those two apps that I haven't been able to update, no matter what I tried, will still be waiting for me lol
One thing you can try, download the apps one by one instead of doing all at once