I'm giving ~1/3rd of my Twitter stock (exactly 1% of the company) to our employee equity pool to reinvest directly in our people.- Jack (@jack) October 23, 2015
As TechCrunch notes, the giveaway is almost certainly aimed at improving the morale of the not-exactly-struggling-but-not-exactly-thriving social network. The company recently announced the layoffs of 8% of the Twitter workforce, over 300 employees, and has experienced something of a crisis of leadership which ended with the return of Twitter co-founder Dorsey as CEO.
The move also is aimed at reinvigorating a workforce that has seen the company's growth weaken as new sign-ups for Twitter accounts have slowed and its place in the social network marketplace has become weaker in the face of newer networks like Snapchat and Instagram, and the utter dominance of social media king Facebook. The company remains profitable, and has recently released a spate of new ideas and products to encourage growth and garner advertisers.
This could actually be a huge boon to Twitter's employees, as some, such as former Microsoft head Steve Ballmer, believe Twitter is actually undervalued. Meaning the stock that was just given away could become much more valuable in the future.
And while a $200 million gift to employees seems very generous, Dorsey still has 2% of Twitter, and Twitter in total is valued at almost $20 billion. So he's still doing alright. I mean, it ain't Zuckerberg money, but he'll get by.