Dr. Mundo's rework makes him the freshest champion while we wait for Akshan's arrival in League of Legends. The rework arrived in 11.12 for one of the oldest faces in Riot Games' world; giving the self-proclaimed doctor new tools and a new look.
While he seems balanced, he doesn't really excel in any role, and is suffering due to his genericness.
What Riot Games is proposing on the PBE is not just a buff; but a complete overhaul. With this, Dr Mundo will no longer find himself in the toplane, instead giving him more tools to compete in the jungle.
All PBE changes:
If anything, these changes will hurt toplane Mundo as his passive health regen has dropped at early levels; while the the buffs he receives have no impact on the role. However, the increased damage against monsters and attack speed will to improve his jungle clearing.
Obviously, this does not mean toplane Mundo is no more, Mundo goes where he pleases afterall, but it is now less optimal.