Just no, absolutely no.
Let’s now discuss actual facts shall we.
First off wow is predominantly a single threaded game, the engine was built when multithread meant multi CPU boards which existed only in the server and high end workstation world. Wow has limited multi threading via engine updates but it’s not like modern games and won’t be unless they completey rewrite the entire game engine.
Now onto your myrid of false statements.
Running on one thread is actually not harmful, and will not lead to anything bad happening. If it bsods or overheats running one core at max turbo you will also crash using all cores because one core at full speed rest at idle means your using 1/4 to 1/8 of your TDP depending on core count and design, meaning that your not even close to the possible heat generation or power demands of the CPU running at full power. Also it won’t degrade it, for that to happen requires high voltage above spec or very long extended usage time, what happens to degrade it is called electro migration. Unless your manually overclocking and boosting voltage over tested tolerance levels your fine. Please do some basic research, as someone whose been fixing computers and troubleshooting them professionally for 20 years this kind of information leads to people thinking they have issues where no exists.
You don’t have a problem