it won't be long until this gets securitized so you can buy a basket of pre-ipo stocks that are at the mezzanine level of funding.
Employee's get to take a bit of risk off of the table, investors get to buy into pre-ipo stocks.
As long as we can create a suitable vehicle to get around the share holder limit, and I'm pretty sure this is a well researched area, I can't see how this doesn't become another securitized product.
If the alternatives are private secondary markets or employee's being locked up util the company chooses to go public then this seems like a clear win.
This fixes one of the biggest problem with valuing startups. Right now startup valuations are high because, just like free agent sports stars, you only need one person to cut you a check for the valuation you want. Meaning, even if everyone else thinks you are extremely over priced you still get the valuation/money due to the one rogue investor/owner. This has the effect of pushing valuation only upward.
Imagine an ETF that pools shares in pre ipo stocks. Now you can take the positions that the unicorns are over priced and short them. This should give us much better insight into what the entire market thinks these startups are worth.
EDIT as pointed out, companies may change their option plans to counter this, I disagree that this will happen in a meaningful way. I think the good companies to work for won't and the bad companies will be left with the choice of hiring only people who can't get better jobs or following along.
30 years ago stock options for everyone wasn't common. 10 years ago, perks like free food weren't that common. Eventually if people are hard to find, companies come around.
You could be right that this will never fly, but I'm betting on the good companies dragging the rest of them along.