Correct they can't match till Free Agency opens.
Why it is important is that Crouch is going to tell them his offers and Adelaide will have the option to sign him to a similar agreement? He is happy for them to match - that is his preference so he can stay.
If they decide to agree to his terms, its all over this week and he stays at Adelaide. That part is pretty simple. Its pointless going through the whole process if the intention is for him stay so it will get resolved quickly.
In the event they don't agree to terms on his contract, its very, very dangerous for them to match a RFA offer. As if he signs and offer sheet and the Crows match, he then has the option of staying at the Crows on a deal set out in the offer sheet or seeking trade/draft. The point being, its his call. Hence, by matching and with his preference being to stay, they are effectively agreeing to what ever is on his offer sheet. Its not necessarily going to get them more compensation, it will help them retain a player. The system was designed to retain players NOT get more compensation and it works well in this situation.
By it not being resolved quickly, they aren't going to match as its too risky they get Crouch for the next five years IF its true he doesn't want to leave and they want him gone.
WE didnt match on Danger either remember