I'm a software developer with 20 years of professional experience, 18 of them on Linux, and 33 years of time spend immersed in technology every day, and I didn't know the N9 ran Meego until I read the paragraph above. I was somewhat aware of Jolla and Sailfish, and vaguely aware it had Linux somewhere there, but only barely.
They probably should not mention the OS very much, and focus on getting people to recognize the brand and reasons why they should want the phones, and only mention "Linux" and "Meego" far down the list.
Stock N9 doesn't even run Meego (proper). It runs Harmattan, a transitional system which is more Maemo than Meego underneath. Nokia planned to evolve it into Meego proper, but never did since it soon sunk into the oblivion of WP. Some parts of Meego (not Harmattan) were forked by the community as Mer, and some other parts (namely Meego Handset) as Nemo. Sailfish is built on Mer and parts of Nemo, adding its own UI on top. All this (including historic evolution of Moblin and Maemo to Meego) can be pretty confusing for those who didn't follow these developments. See also this chart: https://github.com/kumadasu/tizen-history
They probably should not mention the OS very much, and focus on getting people to recognize the brand and reasons why they should want the phones, and only mention "Linux" and "Meego" far down the list.