But... There is a 500 4.0 and 600 5.6 on this list of expected lenses? Only a 400 4.0 is missing, and given the huge number of lenses on this list, not all options can be expected to be served right away.
Are you disappointed that DO isn't mentioned explicitly? I believe if it can contribute to a reduction in size or weight, they will simply incorporate it into future lenses without including DO in the name. See the 800 and 600 mm f/11 for an indication of this. Sure, the DO is mentioned heavily in the marketing material, but it is not something special enough to explicitly put it into the title. Just speculation of course.
The other option is that they can deal with the size and optical requirements better without incorporating DO and therefore just don't put it in. But I personally find the first theory more likely.