I do think that they should not be offered it. Why? Because the proposal would be the result of our industrial action, which many of us participated in. They didn't and should therefore not benefit from it.
I guess the problem for this view is that by being part of a union you accept collective bargaining - so does the company. The breakdown of this collective bargaining is the reason that the company has offered deals to the non-unionised portion of the cabin crew.
Complexity of agreements and contracts builds in an admin burden and associated costs. Unless there is a good reason to operate in a different fashion the company will attempt to reduce any unnecessary cost.
Bottom line, if a better deal is struck with UNITE than has been signed with the non-unionised crew (as unlikely as that is) then expect all crew to be put on the same deal. If UNITE cannot get an agreement as good as the one agreed with the non-unionised crew do not expect them to be forced onto a worse deal.
Perhaps more effort should be put into securing a deal than trying to find ways of punishing those who have a different view on the current IA. Concentrating on feuding is a tradition in the CC unions (BASSA and CC89 reps fighting in the car park), maybe it is time to step away from these outmoded and self-harming practices.