So, not an organization but a cohesive group of likeminded individuals with a specific teaching methodology.
I don't know... Seems to me it's just a dojo. It has its instructors and it has its students as any other dojo. It's not a political party or group or whatever so I am not sure what you mean with the "group of like-minded people " term. It's just that Seagal sensei's approach to the art emphasizes the execution of aikido principles and techniques with a practical application in mind, one that is effective in a fighting or self defense situation with real attackers who will do the best to harm you...
My teacher's approach is in the same direction, yet we have no affiliation with Seagal sensei, we have no organization, we don't call our aikido a specific style-name other than "aikido" and we don't feel like a group of like-minded people...