Very unsure on the validity of the first two videos.
Both actually appear to have been taken in mainland China. All the civilian cars in the first video sport nothing but mainland China license plates. To use the bridge, vehicles need dual plating - HK/PRC.
In the second video, note that vehicles are moving on the right side of the road. and that traffic cameras are set up for same. HK is right hand drive, drive on the left side of the motorway. As well, there's some signage that is very "PRC" in graphical nature - the white over blue with a public safety seal.
Now, I'm no expert, but have been in/through HK more times than I can distinctly remember, and have literally spent years in the PRC starting in 2002.
