If AI training becomes something that only happens with surplus power and takes the place of BitCoin mining non-sense that could really be a net positive.

Maybe it could happen partially, but cryptomining has the advantage that it can adapt to the power available and barely needs any IO, so if there is a single oil well in the middle of nowhere you could use the natural gas for mining instead of flaring it.

I think AI wants large centralized data center with really good internal network.

Are there any research in this area ? Crypto and particularly bitcoin mining has massive capacity for computation , albeit at lower memory scale, if AI memory model could be encode in to blockchain, we can get benefit from bitcoin mining.