I've quoted the email below:
Thanks for the email Our rules team have been very busy working on FAQ and updates for our recently released Imperial Armour index books. Whilst they are still working on a few of the data sheets we have some good news for the ones you are asking about.
The rules team have given us a temporary fix till the official FAQ is released so please feel free to use these in your games of Warhammer 40k.
For the Tiger Shark it should have the following text: Titan-killer: A model with this rule may fire a Macro type weapon whilst moving even if it is not Titanic, but on any turn in which the controlling player elects to fire a Macro weapon while moving it may not fire weapons other than those with the Macro type until the start of the controlling player's next turn.