In the Whitepaper, there is no mentioning of the Coordinator Node, Milestones or Snapshots, which…

• In the Whitepaper, there is no mentioning of the Coordinator Node, Milestones or Snapshots, which are all current features of the IOTA protocol.

Tangle White Paper (p. 9):

Any path from a transaction issued at time t’ > t to the genesis must pass through this set. It is important that the size of a new cutset in the tangle occasionally becomes small. One may then use the small cutsets as checkpoints for possible DAG pruning and other tasks.

Tangle White Paper (p. 19):

From the above discussion it is important to recognize that the inequality lambda > mu should be true for the system to be secure. In other words, the input flow of honest transactions should be large compared to the attacker’s computational power. Otherwise, the estimate (12) would be useless.This indicates the need for additional security measures, such as checkpoints, during the early days of a tangle-based system.

If you replace the word ‘checkpoints’ with ‘milestones’ you will see these things were indeed mentioned. Maybe the fact that a ‘checkpoint’ would have to be issued by some centralized authority during the early days of the tangle for security (ie ‘the coordinator’), is not explicit enough, but I think it is pretty apparent (where else would be the source of such ‘checkpoints’?).