Do you have a reference for the 150M number? Disclaimer: This would've been over a year ago, and I don't remember specifics. I was an engineer, so my main focus was elsewhere.
1) We had a TON of users across many apps and not just our games (many thousands of apps when you include our user-generated ones).
2) These types of numbers were often "sum(MAU-app1 + MAU-app2 + ... + MAU-appN)". This point was always communicated clearly, but may not have been in the press, or could be a source of confusion? Even if communicated clearly, this may still seem like bloating the numbers: but my understanding is it more accurately represents the amount of impressions one would expect (from say a cross-promo with other games, or ad sales) than if you were to de-dupe them by Facebook ID. In other words, say you have 2 games with 10M MAU each, and 2M users play both: it's preferable to make decisions based on 20M as opposed to 18.
3) All apps' MAU/DAU numbers are public anyway, so there's not much to hide.
Thanks for complementing Ravenwood, btw. I really appreciate that. (I was a pre-alpha engineer)
And hey, I'm not saying you didn't have good engineers or artists. I think Ravenwood looked great and creating something like that is no joke.