As far as I know there is only one record of E. albens (White box) for mt Majura and that is a planted specimen close to the lower Hackett water tank see sighting https://canberra.naturemapr.org/sightings/3397854. At this location, a number of non-local Euc species were planted presumably by NCDC and presumably to test which species would do well for revegetation - consideration of natural local ecological community and species was perhaps not that important in the 1960s. There is a record of E. dives for Mt Majura however I can't remember details. I am not familiar with the species and won't be able to confirm from these photos.
Unfortunately, we have a lot of invasions of non-local species such as Acacia cultriformis A boormanii etcs from the Fed highway plantings - I wasn't aware of E. albens. Ciaran how do you know that E. albens was among the species planted along Fed highway? Have you seen a list of species that were planted?
If you ever drive along there the trees in that stretch are quite distinctively different from any othe rlocal species with their greyish bark, see an example Eucalyptus albens (White Box)