Should I really ask questions like that (i.e. which kind of aircraft is used or given passenger route) on Travel.se? Because, that sounds to me a little bit suspicious and I'm getting a very big feeling, that this question asked there will be marked off-topic as well, with a note to ask it here.
Your guess is exactly right. This is a community of pilots, air traffic controllers, aerodynamic engineers, mechanics, and other people who are interested in aviation as an activity - whether professional, or as a hobby. It's not a site for searching for commercial flights, and people here are not interested in helping you find or book air travel.
I can't tell you whether your question is on-topic for Travel - it's very localised and unlikely to be of help to any other visitors - but they definitely shouldn't tell you to ask it here. A question being off-topic on one site doesn't automatically make it on-topic for another site. The Stack Exchange network doesn't aim to provide a home for every possible question.