If AI can do literally any job more efficiently than a human, then there's no need for human labour anymore and at least to me that seems that unless we get a radical transformation of our political economy, that will not be allowed to happen. You can't just put literally everyone out of a job, capitalism just wouldn't be able to cope with it and it'd implode, most probably because of the inevitable backlash that would occur for to no one being able to afford the basic necessities of life. It would be orders of magnitude bigger than either the French or Russian revolutions.
I'm no mathematician, but if being concerned about being able to keep my employment to be able to feed myself makes me a rent-seeker, then I will wear that on my sleeve proudly, crossing my heart, hoping to die. The misery of the alternative is too great to fathom.
Mathematicians acquired their skills over long hours of study, but weren't asking to be paid just to sit around passively being smart, but to keep working on new results. It is the lost opportunity to do work they are lamenting, not the lost opportunity to sit on their laurels. So no, it doesn't sound like rent-seeking.
Sure, there are probably some mathematicians that are sad that robots can do all the proofs and such for them, but it seems to me that most of them probably would be happy with the robots helping to solve problems if not for the little issues that mathematics is their profession and in the current state of things, they need to eat and have a place to live.
And that is the actual problem. Let's just remember, the Luddites were not anti-technology, they were against the technology being owned by a small elite that could use it to take away their livelihoods. They were against the capitalists essentially throwing them into the ditch to starve, and we're seeing echoes of that in the current AI discussion and the reactions of mathematicians, programmers, artists, etc. Back in the 1800s it was physical and artisan manufacturing labour in danger, and now it's mental labour.