I have an acct on my TU report that was included in BK and, as such, is currently "unrated". However, although it says "Incl in BK", the history of 90 day lates prior to the BK are still showing.

I disputed this acct and TU says it is being deleted in 3 days when the investigation is complete. My question: Although it's "unrated" right now, will the removal of this account and it's eleven 90+ notations impact my score at all? These are the only lates showing up on my report.

No. not if even after the lates are deleted its still considered 'unrated'. It will not affect your score.

That was my assumption.