Kobo's advertising about 'no glass' on their own website:
Because Kobo Glo’s advanced high-res XGA Pearl E Ink screen isn’t made from glass there’s never any glare, even in the brightest sunlight.
Non-glass, no-glare, non-issue
Screen - Non-glass touchscreen for glare-free, fingerprint-resistant reading
In my mind, these are fairly clear statements that there is no glass in the Glo. Even if you wanted to limit it to the screen, the glass substrate is still part of the screen, or at least the screen assembly.
Yes, I'm aware that Kobo may be being specific (or vague) enough to get away with this sort of weaseling.
It's like a LCD monitor, where the lighting tubes contain mercury. Advertising that the LCD screen doesn't contain mercury may be technically true, it is misleading, as the product contains mercury.