Actually they started this on Sunday and it worked fine. The only problem was that the toll booths didn't have enough change (for both side, the collector asked if I can provide change to them because they ran out of $5 or combination of $5 coins).
There were only 7 or 8 booths going to the Lantau side to begin with, they closed out the middle sections for construction since there were no booths there previously.
I wondered why they didn't accept Octopus when they started implementing that for other tunnel booths. I'm also surprised they didn't allocate more booths for the Lantau-bound traffic.