I think this both overstates and understates the case. The evidence being weak does not invalidate the decision; as the court notes, the government gets substantial deference on matters of national security.

The invalidation comes from the fact that this is clearly retaliatory behavior for speech; and the evidence for this is fairly strong since the administration has made public statements to that effect.

The evidence being weak means that it is clear that there is no reasonable belief that the cause of action is anything but an attempt to apply a penalty for the use of protected speech.