A little speculation
The fact that Bassa haven't balloted is the most interesting issue at the moment, I believe.
Bassa say that after the meeting the other day between WW and DS, they were consulting their QC. Now if Unite were confident that changes were contractual, there would be an immediate announcement of a forthcoming ballot. But there hasn't. There may be an explanation.
Perhaps DS has been told there is significant risk that BA could win on the contractural question, and has told Bassa that he won't allow the ballot. (He can veto the ballot but can't veto the strike that might follow.) Bassa now find themselves out on a limb, and their only option is to split from Unite, if they want to strike, but will expose themselves to financial ruin in short order if they aren't watertight in their legal argument.
So, they arrange a mass meeting to 'consult' with the membership to explain face to face that WW's pesky lawyers have denied them their democratic option to strike and that Unite have bottled it and let them down. Everyone else to blame but Bassa, but they get a way out without the destruction of the union.
Everyone applauds the magnificent leadership, has a meaningless vote on a couple of pointless resolutions, and goes home.
This is all conjecture, but it fits the picture?