However, it's possible that they prioritized this early investigation to look first at certain categories of apps that may be more likely to get suspended.
Also, it's possible that they are just being really conservative in suspending apps. The suspension sounds like a possibly temporary thing while they investigate them further.
> To date thousands of apps have been investigated and around 200 have been suspended
It doesn't really indicate how far along they are in their investigation. It says they've investigated thousands of apps so far, but we don't know (from this post, at least) how many are still pending review.
The strategy of these firms is probably to launch a series of apps that run the spectrum of popularity, from thousands to millions of users. Banning the big ones puts a dent in the problem, but a company could have released 50 apps with 10,000 users each that sucked down profiles of 1 million people each (via calls to friends' data). My guess is that each of those would not qualify as "large" by Facebook standards.