I am absolutely devastated by this news. I have memories of this attraction from 1996-2013 visits and i'm sad it's future is clouded.
Made use of Disney's free fastpass system although the new system looks neutered. Didn't need it at Universal or Knotts. As for SFMM, I'm gonna disagree with Gazza on this one and say we felt SFMM definitely needed one - but theres a few things to take into account - Gazza has hustle - you can tell from his trip reports that his stamina is up there. I've always gone with family who've had no interest in racing from one exit to the next entrance, so it depends wildly based on your group dynamic (as well as the day you go - we stupidly went on a weekend in May). You can buy on the day but we pre-booked ours as it was cheaper, and at the time the platinum had a limited number available each day. It may have changed. We would not have gotten to ride X2 without it, and given the big distances between some areas, using it meant by the time we got to the ride entrance our reservation was ready and we walked straight up. (Unfortunately, not every flash pass entrance puts you to the front of the line however, so this isn't necessarily a walk-on pass).
Another tip for SFMM - many parks have security checkpoints \ metal detectors \ bag checks before you get to the gate, but SFMM's security check i've always found to be really slow - to make the most out of your day, make sure you get there early to get security check out of the way well before rope drop.