Seems like a non-event to me, people just want to believe these valuations are insane. Are you really feeling that much better that Snapchat is worth $10bn instead of $15bn if you hate Snapchat?
No longer can managers keep selling a dream that was last pitched years ago at their last funding round; they'll have to compensate for underwater options with rising salaries or grants to keep talent around. Certain startups have a habit of delaying sharing bad news with their employees to the very brink of collapse; this behavior will now be in check somewhat.
If you take equity, you are not only subject to dilutions, but also to other investors getting much more preferential terms to you.
I'm not saying to don't take a job because of shares, RSUs, or options offered, but one needs to take a hard look at these things to figure out what their true worth is. And in most cases, you may only be able to compute a confidence interval and not a point estimate.
Fidelity's disclosure makes this seemingly intractable problem a bit less intractable.
Having Fidelity investing in startups adds a whole new layer of public disclosure to the VC world, specially relevant in the light of the large number of stale unicorns.