Hi!
Hmm, if that’s the problem I can’t do anything about it indeed. I do have an Ubuntu device, but on there I have a different issue. I also created a topic for that (Expo isn't working - #4 by adamjnav) I can’t get Expo to work on that device. (that device isn’t ARM) Maybe you can help me with that problem too!
Aaahh, so if Expo is going to work on Ubuntu I can build an app for the first time there and after that on my Chromebook?
To upload the app to the app store I use an online service (https://www.wenz.io/ApplicationLoader) so that problem is already covered. 
If you can help me with the problem on my Ubuntu device too that would be great! Than both problems would be solved 
Thanks!