Can a Specialist be denied promotable status at the board for not having enough correspondence hours?

You were not denied promotable status- you were not recommended for promotion.

Depending on what the members of the Promotion Board is looking for/at...I've seen SOM board members weigh more on appearance than knowledge and vice versa. I have to ask...what did the rest of the packet look like? Was it filled with just the basic requirements? Minimum standards met? Nothing that stands out? Bare minimum Soldier? I ask because if this was the kind of packet I was looking at as a Board Member, then I would not recommend them for promotion.

Yes, i have heard of this. The board looks at potential for advancement and leadership. If you haven't put in the time to complete correspondence courses which help in professional development, what makes you ready to be a leader?