Hm. Doesn’t say it’s an alternative route to a GED or whatever, mind you – that is, not something like a charter school here in the States. It might simply be something like a vocational school, offering an additional credential, hence Ms. Dubuc’s comment about it being open to all ages. The ponies in attendance do seem to be a bit older than the students at Cheerilee’s school.
 
Yeah, that makes sense. There’s the normal public school system and the basic degree it offers, which is probably the standard for a lot of jobs in Equestria, and the School of Friendship is basically a professional credential. I think that’s what she means.

@Beau Skunky  
Nicole Dubuc was the the writer for Marks for Effort and the tweet was telling the difference between Twilight’s school and Cheerlie’s school. Try this link: https://www.equestriadaily.com/2018/06/a-bit-of-insight-from-nicole-dubuc.html

@Background Pony #B4FC  
There’s something you know that we don’t know.

It’s not a school, it’s a temple.

Who is Nicole Dubuc, and what’s the context behind this? (Source link won’t work for me.)

@Background Pony #B4FC  
Wait, what?

I thought it was ‘Mrs’