The cadets are probably going to be from different years at the academy, so most will be twenty-somethings, not teens, plus a few older instructor characters to round out the cast. The setting presumably the 32nd century Federation HQ/Starfleet Academy starbase and the characters will undoubtedly have a training ship of some kind, which they'll take out most episodes to have the usual Trek hijinks. So overall it will probably have a similar feel to early DS9, where there were some young officers and a couple grizzled veterans residing on a space station with little ships they take out to have the usual Trek hijinks.
I actually would like to see cadets at different stages of their lives... late teens, 20s, 30s, etc. Believable because plenty of people start college in their 30s or older. This might help mitigate the show from degenerating to a teen drama in space. Also, if there is any time where it's MOST believable that there would be new cadets from later in life, it's this one set in the 32nd century after the Academy has been basically nonexistent for a century.
Well, if you like Japanese video games and animes, there are a lot of shows and games with the setting of school. Even with their RPG and war theme story, there's still school scene in it. This show can has the feel of some Japanese RPG, like Trail of Cold Steel. Or maybe even one of their space cadet theme anime. Like Infinite Ryvius. That's why I looking forward it.
Not just college, but also the Army. The cut-off acceptance age over there is 41 (which is higher than any other cut-off age in the military). I had a friend who didn't enlist until his mid-30s. This was about 10 years ago. Around the same time him and another friend I have in the Army tried to get me to join! Then I politely told them, "I'll think about it," and didn't. When I was in college, in every class I ever had, there was at least one or two older students. Then I worked at a community college afterwards, in the TV/Radio department, I saw the statistics of the student body once, and this was the breakdown over there: It was 49% under 21, 23% 21-29, and 28% over 30.
A guy I knew who enlisted in his early 20s said there was another guy in Basic Training with him who was 29. Everyone else called him Grandpa.
Clearly after year 4 one of the cadets with become an instructor, and what was once a study group will be rebranded as the Save Starfleet Academy committee.
The Starfleet Academy series is a case of "I need at least a trailer" before I can form a opinion about it.
They can also do the hologram thing and bring back anyone from any era as a guest tutor/stunt casting. We already know Janeway becomes a training holo.
I don't watch The Boyz or its spinoff. But the spinoff's reviews have gotten le more excited for Star Trek Academy.