Thinking about it it actually makes a kind of sense that HT would reveal this clean T1 T-800 before the BD T2 T-800. With the latter probably requiring a unique body (assuming they're not going with 'stick-on' endo pieces underneath the clothes) it was easier and quicker to put this one together while they take the time to perfect the T2 BD. And perhaps knowing it was going to take a while longer to develop T2 BD they were actually thinking of us sitting around waiting, twiddling our thumbs, and wanted to give us something exciting in the meantime.