If you can politely bow out, I would do that. Say you have privacy concerns, or say you are afraid that if your dish(es) appear on camera then illegal scrappers (like the people who steal air conditioners) will steal them or that someone might vandalize them. Just use any excuse that you can to politely decline, without mentioning the channels you get.
If you can't bow out, then what you want to do is frame it as the modern equivalent of the type of shortwave radio listening that hobbyists engaged in in the shortwave radio era. If you plan to let them see your receiver, delete any popular English-language channels that you don't want to see go away (you don't want to flip over to the guide and let them see something that would pique their curiosity). If possible stay on 97W ku and show all the international channels. Whatever you do, PLEASE PLEASE PLEASE do not demonstrate reception of any major network feeds, or any popular subchannel services (the type of services carried on the .2, .3, etc. subchannels of your local channels). Talk about getting signals from all over the world. Make it sound as boring (to the average viewer) as you possibly can. Sound about as excited as Ferris Bueller's teacher. That said, you can slip in technical stuff that might be interesting to other hobbyists, as Cham suggested.
But as he said, "Problem is they can cut and edit the interview as they see fit." If the interviewer decides they don't like you, or they are having a bad day, you and the hobby could be portrayed in a decidedly unflattering way. I let a TV station interview me once about 30 years ago, and I would never do it again. They have their own agenda before they ever go into an interview, and the one little offhand comment you make that you think is just idle banter might be the thing that gets highlighted and repeated three or four times. With enough minutes of recording and some basic editing skills, they can make you look like a total lunatic if they want to. If it were me, I would just say no, politely but firmly.