https://en.wikipedia.org/wiki/Ethereum_Classic
There are no indications that ETC will move to proof-of-stake as planned (for many years now) by Ethereum.
There has been speculation that Ethereum miners would not abide by the upcoming hard fork to proof-of-stake (PoS) and will continue mining on the pre-fork chain.
The increase in ETC hash rate suggest that one outlet for ETH mining hardware could be ETC.
It's likely that both outcomes will happen together post-merge: ETC attracts some ETH miners while ETH PoW chugs on.
Either way, the mining rigs and their power consumption may not be going anywhere anytime soon.
The relative exchange rates of ETC and ETH have not moved much since July: