I think it’s just poorly phrased and what they’re trying to say is that their status as “IBM employee” is a boolean value. You either are an IBM employee (and presumably have some additional contractual requirements) or you aren’t.
No, I think this was pretty standard company-speak for "you're salaried so we own all your creative output, regardless of when or where you create it". Most employment contracts in the bay area (at least) have language to this effect, regardless of whether or not it's enforceable. Even if it isn't, an employer can still make your life miserable over it, and there's not much you can do about it aside from quit.
