It's a warning if it isn't accompanied by great democratization, because the planned economy concentrates a lot of power in the hands of the planners.

Some proponents of planned economy (e.g. Cottrell) suggest that elected democracy should be replaced by sortition for just that reason. Or perhaps there are technical ways to make planning less centralized, say some kind of federated system with freely available real-time production data, where a new producer can decide what group of existing producers to join.