And with that video, I have marked the Cornwall Bypass on OpenStreetMap as open between its east end and the Cornwall Road interchange, tagged as a motorway. Everything west of the interchange is still marked with construction tags because the west end needs to be redrawn and I don't know what it looks like.
Since it's open to traffic, why mark it with construction tags? The part west of the interchange needs some corrections, mainly to show the interchange at the west end, and eliminate the supposed at-grade intersections. But the greater error is to show it as not yet open to traffic.
The interchange at the west end is roughly similar to the one at Cornwall Rd., with ramps from both EB and WB TCH 1, each connecting to a small traffic circle (from WB, just a partial circle, since there's no road continuing north of the circle). There is a small bypassed fragment of Main St. south of the interchange, which is not signed with a route number.
You could also mark the old TCH through Cornwall and Clyde River as PEI route 27. The video shows route 27 markers at the west end of the bypass in both directions.
This photo I took the day after the bypass opened shows a route 27 marker for the off-ramp for Main St., at the traffic circle at the east end of the bypass.