its price will continue to rise as long as ethereum is in pow algo. as soon as the ethereum goes to pos, the ethereum classic will receive a big hashrate in its network compared to before, its price will later either remain at the same levels or it will fall as they would sell it for profit. now if miners behave like ethereum by keeping it in their wallets, that would be a positive development.
There will not more ETC to be dumped if hashrate goes to ETC this is nonsense. Miners will receive less, so less profitable at same price thats all.