I don't give a **** about the match but there seems to be a huge misunderstanding of WoU.
Killing Tooru does literally nothing to WoU, it's not like a normal Stand, if you need a comparison, think of WoU as like Notorious Big, a Stand that will exist forever even after the host's death, it's a natural law of the universe, as long as calamity exists, so does he. He's abstract, Tooru dies? He doesn't care (or well he might care in the sense ya just killed his buddy but ya know what I mean). Killing Tooru does more harm than good, at least with Tooru around WoU has a weakpoint, killing him gets rid of it permanently.
Secondly, Gappy killed WoU using a super special power that surpasses the laws of the world in a joint combination of literally not existing + logic defying powers (making it so it's logic surpassing while also being nothing at all) allowing it to completely ignore and destroy chains of logic, which is also why WoU fled, he knows when not to risk it and he had already won (In that he got the new Rokakaka, he never cared about killing anyone, they were in his way is all), given he got what he wanted and Josuke manifested some broke ass ability that can ignore calamity, he was just like "yeah aight im out". If his opponent can't do anything to him, he won't really need to flee I guess? Not saying that's the case here but WoU doesn't just up and leave, and even if he did, it wouldn't even be self BFR because his ability is automatic and can take effect even while he's long gone. Not to mention WoU didn't even **** off after Tooru died, he just doubled down, he was trying to leave before Tooru died, not after.
Though I ain't debating this match at all I'm just pointing out WoU don't work like you think it does.