Theres a Dutch study indicating that we're rapidly approaching supply chain limits for the rare metals required for renewable energy, both solar and wind. I wonder how long renewables can continue dropping in price.
But it also seems to me this might be a cost issue... it's possible that neodymium magnets are used because they're cheaper in context than ceramic, alnico, or other materials. That could change if neodymium prices increase substantially due to scarcity.
It's completely possible that current windmill designs are only possible with neodymium magnets. We would need to ask turbine designer.
Silicon PV (which is 95% of the market) uses no rare elements except silver for front contact wires, and that can be substituted for with copper if a diffusion barrier layer is added to prevent its reaction with silicon.