A few comments:
(1) Math journals are being flooded with AI slop papers loaded with errors. I can see a time when they will require papers to be accompanied by formal proofs of the results. This will enable much of the slop to be filtered out.
(2) Formalization enables AI to do extensive search while staying grounded.
(3) Formalization of the historical math literature (about 3.5M papers) will allow all those results to become available for training and mining, to a greater extent that if they're just given as plain text input to LLMs.