This was probably more trouble than it's worth, but it's all typed out now, so I guess I might as well post it.
Here are the statements that were made:
In the FAA world, if you look at the airport you’re departing from, and there’s no “Inverse T” symbol, then there’s nothing published in the “Takeoff mins” section and you can use a diverse departure with standard takeoff mins.
If there is an “Inverse T” then there is something published in that section, and you have to go look at it. In there may be a textual ODP, non-standard takeoff minimums, climb gradients, close-in obstacle listings or any combination of those.
If there are no non-standard takeoff mins published, then standard takeoff minimums apply. The absence of takeoff mins automatically means that you can use standard takeoff mins.
When considering a takeoff from an airport at which no approaches are published, someone who didn't know any better could reason as follows:
There's no approach plate, so there's no "T" symbol, and the first conditional in blue is satisfied. Therefore I can use a diverse departure with standard takeoff mins.
Furthermore, there's no entry for this airport in the Takeoff Mins section, so there are no non-standard takeoff mins published, and the second conditional in blue is satisfied. Therefore I can use standard takeoff mins.
Those would be dumb inferences, but I've seen worse. The limitation of the statements to airports that have at least one instrument approach is probably implied, but I think it's an important enough point that it needs to be explicit.