The most likely case here is that new manufactured hardware would be development kits, consoles created specifically so game designers know what they're working with. Microsoft said flat-out it wasn't debuting a new console at E3, so rumors regarding new manufactured boxes probably wouldn’t stack up to a reveal.

If we're under the assumption the Durango will release in the next couple years, potentially at a shockingly low retail price, it makes sense that game companies would be working with new development hardware now.