The demo isn’t from 6 months ago
1 echerum’s face still looks like rubber
2 the brutes in the gameplay trailer still have no facial expressions
3 the mangler looks better
4 the bulldog and commando look basically the same just darker which is likely do to differing times of day during the demo and the gameplay trailer
5 the assault rifle looks better
also it was confirmed by 343 it’s only a few weeks old
the idea that it was a 6 months old was just wishful thinking