That looks possibly more like the juvenile foliage of E. macarthurii or some other non local euc from a nearby planting to me. E. aggregata tends to have petiolate, and ovate juvenile foliage (sometimes opposite but not for very long). These are sessile, opposite most of the way up the stem and lanceolate. It would be worth looking at the other potential candidiates in the nearby plantings to get a putative ID
Interesting - we would need a Eucalyptus specialist on site who checks out the saplings and the planted trees in and along Valour Park. I can show the mature and juvenile specimens. I will collect material just in case. MLH can you suggest a specialist who can help?
Having thought about this a little longer, I should add that E. aggregata is known to hybidise with candlebark and ribbon gum...... which is one of the threats to the species when it reaches very low populations sizes. I am not that familiar with the leaf form of these juvenile hybrids but it is very possible that these could be in that category. Alternatively given we have no idea the provenance of the planted trees in this vicinity it could just be that this is an unusual form of E. aggregata (which is a variable species in juvenile leaf form anyway) .