I had set an appointment up a while back due to hardware issues with my camera. I was not able to make the appointment, and now my screen is cracked. Will I still be able to replace my device due to the hardware issues?

That is a decision Apple will make. I'm not sure if the appointment and reason still will appear in the system, but I can say that with a cracked screen, you would at least have to take care of that first at your cost before they would consider anything else. The screen is user damage, but if the camera still does not operate, there is always a chance of a replacement, but don't be surprised if they refuse, saying that it could have been caused by the breakage. I know you are going to say that the one was before the other, but unless there is a record of the issue, it could be your word against theirs. Either way, you are going to need to see Apple.

True. Its really up to Apple. However, you didn't say whether its your front camera or back, if it was the rear, i don't think there should be a problem as long as they see no damage in the rear side of the phone. But its not up to me, its up to apple.

I believe you meant to respond to the OP, and not me. Since I was not the one experiencing the issue. Just so you understand, that user damage on a device can generally result in the denial of a warranty replacement, whether it appears it could be caused by the user damage or not. Just because it might be the rear camera issue, even if the rear of the phone is not damaged, a drop that is enough to crack the screen could be enough to damage internal components of the phone. That is why in cases like this, it is generally stated that the decision is Apple's.