The only thing I would take issue with is that they haven't withdrawn funding (or at least they can't tell us how much funding they are saving) they have withdrawn support for Friends of Group Task Days.
OK, I think I get it - the council doesn't provide actual cash for the task days, but resources in the form of staff time, machinery, materials, plants etc? But in the end, of course, it's still about saving money, so the council should be able to quantify the saving in staff costs (number of park staff to be made redundant), savings in the repair and replacement of tools and machinery, and reductions in spending on plants and hard landscaping materials.
But when you spell it out like that, you realise that unless the council intends to allow the parks to become overgrown jungles, then they will still need tools, plants and materials, and they will need more staff, not fewer, to replace the volunteers who have been lost. So there may not be a saving at all.