I don´t remember what aspect is/means is taught when we learn Turkish grammar at school. Probably they  think it is something more confusing to teach than helpful.

I was just wondering if this use of present progressive corresponds to be going to future in English.

I dont think so Abla, as when we replace it " ;

1. We need to indicate a specific time ;

Yarın akşam saat 6´da sana geliyor olacağım ----> I will be coming to you at 6 tomorrow  evening .

That means, I will be in the process of coming to you at 6 tomorrow  evening.

the Future Continuous is interrupted by a short action in the future

- In "geliyor olacağım " the action has not started yet.

- In "geliyorum " the action has started imaginarlly "