...would appreciate contributions in the forms of parks, recreation spaces, plazas, etc to offset the loss of same when new buildings go up
Replacement of lost parks, recreation spaces, plazas, etc. would seem to have no relevance to this discussion. Parks, recreation spaces, plazas, etc. aren't being lost. Downtown residents have recently gained a new park behind the courthouse and an improved park on Mason Street. Downtown residents have had a potentially fantastic park sitting right there for decades in the form of the Harris Green itself.
I think you're expressing one of the key misconceptions about the redevelopment of parking lots and other null properties. In the vast majority of examples, absolutely nothing is lost. There is only gain. New homes, new businesses, new spaces. If you do redevelopment properly then there shouldn't be any negatives that need to be offset. It should all be good.