Nope. That handling a PR situation like this is either unnecessarily foolish or inaccurate or perhaps a little of both. If you want to be taken seriously, particularly by people with a pile of money they'd like to make larger by investing, then this sort of herky-jerky message managing does not send the right message at all. It's just plain weird. No one thinking of investing would look at this 11th hour 'well everything is great but we just don't have time for this now' and not wonder WTF these guys are doing or what else is going on.
When we look at a start-up, a vendor, a new technology, or any in-licensing opportunity (due diligence) we assume a priori that we are seeing what we are seeing the best possible light. Our job is to kick over all the rocks and see what is underneath. In this case every rock you turn over has something weird hiding under it. This engine unveiling was perhaps the most important material event other than the plant acquisition to happen and it did not happen.
The only folks I'm questioning for their real reasons are the management team and their public relations group. And if they come around an unveil a perfectly good engine in a week to no formal announcement at all, then it'll be clear that their PR group and management team are just inept - not at designing a working engine - but at properly buidling a reputation for believability. And I will cheer loudest of all.