My sense is that IHL is behaving consistently: they announce things according to an internal strategic timetable that doesn't seem to place a premium on short term SP. That said, it may do so punctually when short term SP is strategically important... but that may not be the case right this minute.
SudOne possibility is that Sud is not ready to convert his options yet, and an announcement of more specific timing of the imminent US listing might serve him better when he is. This form of 'keeping their powder dry' for just the right moment, whatever that moment may be, is something I'm willing to assume is at play here, given their track record.
ASX300
The pool of smallcap Australian investors is quite possibly saturated at this point. I know that's the case for me: I have no more buying power. We may be at a point where the only thing that brings more Australian investment in this current market, short of drug trial results or a US listing catalyst, is entering into the ASX300. The next evaluation for admission is in September and this may be part of their timing for the US listing announcement too. A publicity blitz would be well-timed towards the end of August/early September.
US-facing
We know the BOD is now predominantly aligned to a US schedule and goal posts.
For US investors who might purchase on the ASX in advance of the US listing: it may be part of the strategy to engage a specific group of them to coincide with ASX300 evaluation, and option conversion timing. In the Northern hemisphere, August is a quiet month: early September is when everyone jumps back in the saddle.
Publicity spending may now be mostly geared towards the US, and given it isn't quite yet time to blitz there... a calm before the storm exists.
I think a mixture of these considerations is far more likely to be behind the current lack of publicity, rather than anything being wrong, or the BOD's actions being ill-advised.