Ann: Voluntary Delisting from ASX, page-12

No.

The usual process is for significant (price sensitive) news to be released during a trading halt. The 20 minute delay will fall within that halt; there's very little advantage to be had by obtaining the news that little bit earlier.

As for the share price delay, if you're worried about that, there are brokers that will let you pay a little more to access real time information. CommSec will give you that real time information for free if you have an account with them. It's mildly annoying, but not an insurmountable problem, and definitely not insider trading.