Does the person who made those messages not understand that Movement does not = Organization.

Unfortunately there are some Organizations that fight for Khalistan using violent methods, but there are also organizations that fight for Khalistan using democratic ways.

If we use Indias freedom movement as an example, there were some groups labeled as terrorist (e.g. Bhagat singh was labelled as a terrorist because he did kill people for his political goal), but I dont think it would be a fair statement to say the whole Indian freedom movement was a terrorist movement.