Are Stern actually applying this 'fix' from the factory?

From what I read it doesn't seem like it.

Surely the zip ties are there to hold the spacer in place (the thing that prevents the damage)??

If I were you I'd either add a spacer or glue / epoxy. Whilst less than without the tie, a tie alone under tension without a spacer will vibrate quite a bit more than with a spacer acting as a dampener - which it will, whether that was Stern's reason for specifying it or not.

The primary concern is to stop them failing in the first place. With no fuses, and no documentation of any of these boards, damage to other components is quite likely, and being able to repair the board very unlikely.

But it's entirely at their discretion.

Also, that they haven't begun shipping revised boards in newly shipped machines is extraordinary. Zip ties / glue are now standard 'factory' spec?

As the above poster's experience tends to hint at, application of them or their efficacy is far from fool proof either, so there will still be ruined boards.

Exactly how cheap are the boards for them to choose to do this instead of a minor respin with more durable mounting / components? Or if they really wanted to push the boat out, some fuses. Almost certainly cheap enough to be a minute fraction of the (high) cost they charge for replacements.

Also, from what I've heard, the going price for a Spike 2 MPU board in Europe is €1200 ($1400). Retailers here must provide replacements due to consumer protection law. But Stern are adamant that warranty / guarantee replacements are non-transferrable, even in EU (where that's illegal). So if you sell your Spike/2 machine to someone, and parts fail, the reseller / distributor is then between a rock and a hard place, because they're obligated to provide replacements, but would then have to pay Stern an obscene price for a replacement.

In 3-5 years time when MPU boards and node boards begin failing en masse, what are people going to do? If your MPU and, say, half your node boards drop out on a Spike2 Pro, it's essentially going to be a write off and not worth replacing. It'd be cheaper to part it out and buy a new machine.