So, I can see the rationale of trying to extract more value from those who are chasing status. But at the end of the day, status is an irrational behavior on the consumer side.
Taking myself as an example, I rarely even look at non-AFKL flights if they fly a route. I know that I am paying more on many routes compared to LHG, but given my status, I find it worth it. Over the years the J fares (like every other one) have trended upwards, making the €/XP go up anyway. On most of my regular routes there is an increase of at least 30% compared to just a few years ago, and that number is 30% only for very early promo fares. Normally, it is much higher. So the XP model has already given them the ability to charge more per XP.
However, the options in this survey imply that they are now considering eliminating XP from some fares altogether, or push them downwards in value, while giving more for higher ones. This is where my irrational behavior stops because not only will I now need to swallow a >30% price increase, but even more to just start chasing status. At that point, this family of 3 PFLs and 1 Ulti that flies quite regularly, and controls 100% of its flying spend itself, will happily look at other airlines as well. There is only so much you can squeeze even your "loyal" fliers before they walk away. BA's changes are a great case-in-point. If they were to keep qualification requirements stable, and keep the floor of XPs the same way but start adding bonus XPs to higher fare brands, I would still consider it a poor choice but would still continue to fly AFKL. But without a doubt, if XP disappears from J fares, or they get knocked downwards, or if AF starts doing more compared to KL, I can see a good number of people just walking away from FB.