Facebook has multiple VPs of product. So does Google. This is common...
Off the top of my head:
Twitter App- Web, IOS, Android, Other
Twitter API
Twitter Firehose
Twitter Advertising
Twitter Analytics
On the other hand, losing this many execs in this short of time almost never bodes well, which means their stock price is going to tumble even further without something drastic happening soon.
Because advertising on Facebook and Google pays off.
Twitter, afaik, has struggled to be a relevant ad platform.
Now, if you want to talk about the $2.5B expense line....