I'm a BGO so will try to help but need to understand your question. Does your son have specific questions for the BGO that are going unanswered OR are you concerned that the fact the BGO isn't in frequent contact with your son is a bad sign in terms of his appointment chances?
Some background. BGOs are volunteers and most of us have demanding full-time jobs. Our primary job as a BGO is ensuring our candidates receive their BGO interviews in a timely manner. Secondarily, we do our best to answer questions from candidates in order to assist them in their application process. Most do their very best to be reponsive to candidates. To be honest, some are better at this than others.
Here is my approach, which I think is pretty typical. I email all my candidates (usually 12-20/year) as soon as their name pops into my system. I introduce myself and offer to answer any questions. Then, once they have 1/3 of their packet complete, I email them to schedule an interview. They are free to bring their parents (most don't) but I want to meet with them individually.
At the interview, I tell them that the application/nomination process is complex and lengthy and that I'm here to help answer any questions they may have (other than medical, which we're not allowed to address other than in a general sense). I indicate that the first step in showing you can handle a SA is to show you can meet the deadlines, etc. of the application process, so I won't be sending them little reminders. After all, I won't be there during plebe summer to remind them to get their uniforms pressed.
Finally, I tell them that I will be the last to know if they receive an LOA, appointment, etc. Which, BTW, is true. They know well before I do.
In most cases, I never again see the candidate other than maybe to present their appointments at a school ceremony. Usually 2-3 each year email me with questions to which I respond as quickly as I'm able. I've had a couple over the years who've asked to meet with me again re various issues and I've been happy to do so.
Thus, back to your original question. If your son has questions that aren't being answered, he should contact CGO directly or possibly post them on this forum. If you're wonedering why the BGO isn't calling all the time or shepherding your son through the process, he (as I do) may simply have a different view of the role of the BGO/ALO role than your ALO.
Also, it USED to be the case (do NOT know if still true today) that ALOs were reserve officers whose job was USAFA recruiting. If so, they should clearly be more active. However, in fairness, this may have changed and it may just be that your son's ALO is more involved, has more time, etc.