Whatever could produce something entirely out of itself in such a way as to divest itself of nothing would have to contain all that it produces within itself and continue to contain it.
This is analytic and borders on the tautological. It is arguably a counterfactual truth, but a truth nonetheless.
Creation is to produce something entirely out of oneself so as to divest oneself of nothing.
This is slightly more controversial (there are Eastern-influenced accounts of creation that consider it as a sort of divine self-divestment or clearing of a space for creation) but it is not even clear that such an account would count as “divine divestment” in a sense that is in play here.
So whatever creates contains all that it produces within itself and continues to contain it.
What creates contains what it produces in a complete or perfect way, and so contains any good that the created seeks in a complete and perfect way.
In this sense, the creator must be desired by the creature. No matter what a creator created – even if he made a whole race of persons to experience infinite pain in Hell from the first moment of their existence – he would still have to be seen by such persons necessarily as good.