So I was going through the new rules and I came across something I’m unsure of. The rule states that it provides cover if you fire “through it”, but what if your models are in it. Is it considered “firing through” if the models are in it shooting out?

If you're in it, the defender won't get cover because your unit leader is touching the terrain. But you will get cover in return because some part of the centerline passes through the terrain.