I think there is a reason but it involves some empathy in order to logically understand.

We know he has been working on it for a long time, a year prior to launch.  Personally, I think he would have waited even longer if there wasn't a modicum of excitement and/or a need to start testing his code with an operating blockchain in real time.  Keep in mind, a ton of basic work went into his project before he even revealed that ZT was a thing...months.

Further, considering the more or less common knowledge that he is a 20 year vet within the P2P field, the decision to embark on this project as a full time job probably was made with much consideration.  Involved in that consideration was a knowledge of what the altcoin community is like.  Think about it for a second.  This is a terrible community.  Scams are everywhere, collaboration is close to 'not so much', scam devs are copying code and releasing new coins with promises in order to get the first 'spike pump' and then leave, and most of the threads in the altcoin community are peppered with inane BS that no sane person would tolerate in a normal social forum.

Chances are, he is very well aware of how toxic some aspects of the altcoin community are and has every intention of releasing material...but if it isn't ready then it isn't ready.  Further, providing misinformation, or mystery, is potentially a valid way to gain information on the community that he is working in tandem with.  I use the phrase 'in tandem' very loosely because the interaction is necessary but there is no real collaboration between devs and speculators.  It is an important distinction to make...

 Jump into IRC and communicate with him - he talks every day.

If he says the white paper is coming with actual math (he posted a paragraph a few days ago) then it is coming.  He started this project wanting no hype and went months without it.  Very productive months.

It sounds fishy because you are used to a crypto alt scene that is fishy - I'm sure he thinks the same thing.  The thing is, he has delivered everything he has promised and then some.  Some of you seem to forget that he just released the bitstream for FPGA...do you have any idea what that means and how many other devs have done that (None)?

Be patient and see what happens...

Edit to add - I like the VNL community and aspects of other communities...but to be honest, there is no stopping people from muscling their internet posts.  Tis the reason why I referred to it as terrible.  Valid disclaimer and one that should be met with reflection rather than indignation...