knavesmire
The oversimplified questions you are asking seem to suggest you are not following the extensive discussions on this subject, over on the BALPA web site, and also in correspondence from them.
Perhaps you aren't a member?
For example, you suggest the legislation seeks to increase CRAs from 55 (in BA) to 65. This of course is not true. Should the legislation (not yet finalised) be implemented, a retirement age of 65 would be every bit as illegal, as one of 55!
If you want to, have to, must; you may work 'til you drop/ fail a medical.
I suspect you may have a reason for wanting the law to be implemented promptly. This being the case, I suggest you refer to BALPA.