As I understand it, nobody holds stock anymore, because he took the company private. He bought everybody's shares. So whatever portion of employee's comp was equity, that's now zero. Elsewhere, I saw somebody estimate that to be around half of twitter employees' comp -- I have zero confidence in that estimate, but it doesn't sound unreasonable.
And while they might get a lump sum for whatever equity they held, that's money in the bank and no longer a carrot.
Existing equity was converted to cash at $54.20/share, but will still be paid out on the existing vesting schedule. It's a carrot, insofar as it is promised future money, but it's a decaying carrot.
Edit:
Yes, the proportion of total comp that was equity hit about 50% at L7 (Twitter's Staff). L6 (Twitter's Senior) was usually around 40%.
And while they might get a lump sum for whatever equity they held, that's money in the bank and no longer a carrot.