I think it is more likely that they simply didn't started full production of NuFallout4, maybe even not before 2012 or 2013 even. And beeing for 2-3 years in crunch time. Is it so unlikely? Consider this, Todd himself said that he is proud about what his team is doing while it is so small compared to current industry standards. I guess he must be talking about Rockstar and EA, can't be Obsidian or even independed developers, which have even smaller teams than he does. And I guess when he says 100 people it is probably more like 70 or even less, since in gaming it is very common to hire freelancers. But I digress, again, it is all just a guess.
If he says that they worked 7 years on it, than I even believe him! Their concept artists probably started to work on Fallout 4 as early as 2008 or 9 eventually, before Skyrim was anounced, while their core development team didn't start anything Fallout related before the last DLC the first Dragonborn was shiped. Which was for PC in 2013! Remember, Skyrim didn't saw much support during that time either. Who knows? Maybe one of the reasons why they even decided to hire another team. We can not know this for sure of course, but it would not surprise me if those last 3 years have changed something here. Definetly not so much that they want to suddenly make true RPGs, but enough to realize that they hit a limit somewhere.
Oh, I am pretty sure, just like Toront, that they are NOT lazy developers! I would even say quite the oposite! A relatively small team, some missanamagent here and there, with wrong priorities and project leaders like Todd, Emil and Pete that I consider walking suits, only interested in sales numbers, and not game developers. Not much of a surprise Fallout 4 really ended up as what it is today.