Who are you people to know what LFS does and doesn't need? (I'm not reffering to Tristan who obviously got the picture right)
And my opinion on this topic is that I would welcome the addition of american muscles cars, because I have no chance of driving one irl and LFS is as close to reality as possible on PC.
However, I pretty much doubt that it will be included because it has no perspective in LFS racing. Muscles cars are just toys. You'll play with them for a while and after finding out that they're mostly rubbish, you'll leave them be.
And if I offended a muscle car fanboy, then...I like Lambroghinis, bash them in return, I don't care anyway