Perhaps. But perhaps it will create further economies of scale for renewable energy which will accelerate adoption of renewable energy. The more renewable energy that is used, the cheaper it gets, wasted or not.
We now know that there is a cartel of US miners trying to create "clean" bitcoins (in part to appeal to Tesla and Musk) that will sell at a premium.
https://www.bbc.com/news/technology-57240090
This could increase the pricing differential between clean and dirty electricity sources. However, most utilities don't care and so will buy the cheaper electricity, which means that there won't be a significant push to decrease fossil fuel based generation.
Unless demands from bitcoin mining start to strain clean electricity generation, there isn't really much reason to build more renewable capacity either. The kind of thing described in the OP (the repurposing of existing facilities) is likely to be the main result for the foreseeable future.
"Clean" bitcoins are just "greenwashed" bitcoins.
We need less greed and a co2 tax which makes it undesirable to mine Bitcoin over producing energy which actually does something for our society.