The land is Council-owned so Forest Lodge owners/residents have no rights over it. It doesn't have drop kerbs along most of its length either, so the parking that has been taking place there has been on an informal basis. However I do sympathise with the people who currently park there, and those who live on streets which will receive the displaced parking.
That said though, my family and I walk past Forest Lodge along Dartmouth Road on a daily basis, and the parking there is problematic to say the least. There shouldn't be vehicles manoeuvring around the rear of a pedestrian crossing. The crossing itself has suffered three of its four protective wooden bollards being destroyed by cars. Similarly there shouldn't be cars parked and manoeuvring around a bus stop. But even taking these two particularly sensitive areas aside, it's also fundamentally unsafe to have cars reversing out onto Dartmouth Road across the footway. Antisocial parking is a frequent problem too, with vehicles often partially and sometimes fully blocking the footway. All in all it makes it a pretty rubbish place to walk.
During the design development, parking bays between the footway and the carriageway (i.e. not involving vehicles crossing the pavement) were investigated by Lewisham Council and their consultants along the stretch of road from the bus stop to the crossing. I'm not sure why these haven't made it into the final design, but I suspect that they failed the safety audit. In any case, they wouldn't have matched the numbers of spaces lost, so the issue of displacement would have occurred anyway, albeit in lesser numbers.