There’s nothing that I’m aware of -
Intertube will show you what is running at the moment, but that’s about it.
Line working timetables are published showing all empty stock moves etc., although these are only valid when there is no engineering work. This will include Met line Rail Adhesion Train runs (D stock) during the appropriate period, but does not include engineering trains, heritage trains or the Central (or Piccadilly? I need to double check that…) RATs, which run to different timetable methods. In theory these will all appear on Intertube when ‘live’, but not always as you’d expect.
TfL’s open data is excellent, but doesn’t cater for enthusiast-style demand as it isn’t its primary purpose, and nor does the data exist in the same form as passenger workings internally.
You can FOI some things (such as engineering timetables), but there’s no guarantee they’ll be released ahead of time.