The reason why BA (I think) will go to court is to sue Unite for losses incurred on the basis that this strike is related to the last. And I think they will do this first before they take any action against striking cabin crew.
It doesn't close any doors to them with regard to dealing with strikers but it does mean that if they win against Unite then they know that they have all options open to them in dealing with the strikers with little chance of any future action against BA being successful.
And I think it will be less damaging to the company to take the Union to court rather than to immediately sack strikers. But if the strike is deemed "illegal" (ie the strikes are linked), I suspect any public fallout from sacking strikers after that would be less. Just personal opinion.
BA could potentially have their cake and eat it - having Unite fund the removal of the strikers from BA.