BCW0012: WARNING: 'UnityEngine.MeshCollider.mesh' is obsolete. mesh has been replaced with sharedMesh and will be deprecated

Does this mean all `mesh` should be replaced with `sharedMesh` ?

WARNING in reference to: `unappliedMesh.GetComponent.().mesh = unappliedMesh.mesh;`

Full code is just an explicit typecast of the paintvertices.js that comes with the Unity procedural examples zip. Modified paintverticies.js @ http://pastebin.com/rnKWttxv

Yes. Deprecated means it's soon to be discontinued. Instead of using mesh, use sharedMesh. Normally you mark members or types obsolete to give a grace period for developers to change before pulling the plug on the old member/type. If they simply just removed mesh it might been unclear why it was removed and what to use instead, and the project would suddenly no longer build.