They exist, but not in the traditional retail 401(k) menu-driven marketplace (including a "brokerage window" as one of the menu options). I agree with ESOP Guy that you are unlikely to have options available despite legality as a retirement plan investment. It has nothing to do with employer securities, as such.
While it might be legal I have never seen a plan that allows it. Plans aren't required to allow all legal investment choices. If this plan does, great but I wouldn't hold my breath.
I've sometimes taken the position that such trailing dividends as well as the resulting payouts were "pending" - I guess you could call them accrued. I'm not saying it's right and ya takes yer chances I guess but...how is it going to come up in the first place, and in the second place, I think I could talk my way through it if necessary.
Sux that this would happen after the plan was term'd in September...