In the past 12+ years BALPA has never even had to threaten a ballot. Why? Because pilots and the BALPA leadership are intelligent enough to analyse any proposals carefully and act accordingly. In short we are neither short sighted nor suicidal.
I have no doubt Bidline rules will be modified, they have been on a regular basis since their introduction, and I can also think of areas that will come under scrutiny and will no doubt change in the fullness of time. What you won't see is pilots setting off half-cocked over a raft of non-issues for some obscure undisclosed political reason.
If a matter was serious enough and the management was short sighted enough not to listen and engage with probably its most loyal and long term group of employees then watch this space.
BALPA and the BA management have been astute enough to avoid that situation during the most difficult negotiations seen in recent memory (pensions) and I have little doubt that sensible situation will continue.
So what has changed between now and a few months ago. Well numerous meeting between the company and balpa, with the company saying this is all that is on the table, analysis by the actuaries, balpa getting expert advise[sic] etc. The reality is however that Balpa have been convinced that this is all that can be afforded by the company.
You answer your own question and conveniently overlook the fact that only approximately 70% of the pension everybody was expecting would have been able to have been paid anyway because of the dire funding crisis.
It should be noted from previous posts that it was said that the GMB and BASSA were posturing over the proposed pension deal. That has now been partially proven, keep watching.
If I was of suspicious mind I would have thought that your post was attemting to stir up dissent where non existed before.