If Airbnb has handed 10 year expiring stock options to core employees, then they're right at the cusp of expiring this year.
I would guess it doesn't affect anyone who opted for an 83B early on, but for those who held onto them without exercising them on the pennies might be very unhappy without a 2020 IPO.
It feels like a different era now, but this was discussed in detail in late 2019 [1].
The discontent has been exacerbated because Airbnb, which has been valued at $31 billion, doled out two tranches of employee equity that are set to start expiring in November 2020 and in mid-2021; those shares will become worthless if the company is not trading publicly by then, they said.
[1] - https://www.nytimes.com/2019/09/20/technology/airbnb-employe...