Simplifying a lot, but...

VC companies themselves raise money from investors to create a fund, which is then used to invest in startups. Generally, funds are raised with a specific timeline pitch for returns to the investors - often 7-10 years. In order to return money to investors, the investments in the fund have to actually pay money back to the VC firm - the best way to do this is via IPO (although acquisition is also an option).

Due to overall market conditions, a glut of investment happened in the VC space 7-8 years ago (i.e. a bunch of funds were started), and those funds now need to get money back to the investors to prove a nice ROI, so there's a push to get the startups that were funded by the fund to exit one way or another.

When a VC raises a fund, they usually try to return the money in 7~10 years after they start deploying the capital to startups. In other words, they want to exit their position no later than 10 years and usually shoot for 5~7.

Not that dude but ~11 years ago was the recession so I'm guessing he's alluding to the fact that lots of investment money comes out of hibernation all at once when recessions begin to recede.

The best place to learn about this is to check out the memos Howard Marks has written over the years.