Originally, even pre-eao, a signalized intersection was to be situate at either 72nd or 80th, which could be upgraded to an interchange when traffic warrants.
That signalized intersection was moved eastward to a new alignment called "Tilbury", which has since been upgraded to an interchange.
BC MoT recently had a "PowerPoint" presentation at the Delta Chamber of Commerce whereby Slide 4 (of 15), confirms a 72nd underpass and an interchange just east of there at Tilbury.
http://www.deltachamber.com/chamber_business/news/news10160901.aspx
As for Hwy 17 between Deltaport and Ladner Trunk Road, that one still leaves me wondering. I sincerely hope that it will remain a 4-lane divided expressway but something tells me that MoT might remove half the roadbed and turn it into a 2-lane highway to disuade traffic from utilizing the corridor due to residential concerns at Ladner Trunk Rd.
I hope that I'm wrong!