In their post on the Ubuntu blog [0] they say it is pronounced "or-well". Assumedly ironically.

[0] https://insights.ubuntu.com/2016/09/29/meet-orwl-the-first-o...

The name is from Orwell as you guessed. The idea is that we need an open source computer that protect privacy to enable freedom of speech ;-)

Considering their video starts off with a quote from George Orwell, I would say the pronouciation is intensional.