There's nothing in TFA that hasn't been speculated in great detail already.
No explanation totally makes sense. Here's my working model of what happened (all speculation of course):
The project has been gradually disintegrating over the last few years -- developers leaving and not being replaced, remaining developers having less time to spend on the project for whatever reason, and the perceived reward for fixing increasingly difficult bugs is not enough to keep people interested. It's just not fun any more.
The to-do list has some really nasty bugs that are difficult to fix and could potentially compromise all TC containers. The remaining developers in the project have been grinding away at these bugs, but haven't made much progress for reasons outlined above. They realized that the project was going to fizzle out before they got anything fixed. A cursory look at the 7.2 code suggests that they had committed to some major rewriting of the code, and bit off more than they could chew.
At this point, what can they do? Reporting the vulnerabilities would be irresponsible since no fixes are forthcoming. Lives depend on some of the secrets their software keeps. Best to push people gently away from TC until the problems can be fixed, if ever, while keeping the details of the vulnerabilities as secret as possible, and giving people realistic expectations about the future of TC development (i.e. none).
They probably had a plan for creating a migration plan that actually made sense, but ran out of resources before finishing, and decided to go with what they had on hand. At this point they were probably down to one very part-time developer and maybe a few unreliable volunteers. ("Hey Jim, where's that page you were writing about Linux FDE? Jim? Hello? Anybody there?")
There was really no good way forward with the resources remaining, so they did the best they could.
Why didn't they find someone else to take over the project? I guess they tried, but couldn't find anyone in their immediate circle of trust who was willing and able. Perhaps they felt that expanding their circle of trust would jeopardize their anonymity.
On the other hand....
"WARNING: Using TrueCrypt is *not *secure *as ..."