That is correct. Raw footage can be decoded directly to ACES, without the need for an IDT. In this case, most raw decode parameters are disabled, as they are irrelevant. You can still alter some, such as Kelvin, Tint and ISO.
The exception seems to be Sony Raw, where Resolve does include a Sony Raw IDT. However I have found I get better results (matching other implementations) on F65 Raw media when I use my own DCTL S-Gamut3.Cine IDT. See my other post on this subject.