Earlier quoted context omitted.
HN ran on a box at Softlayer until early 2018 or so. This makes me think that the title of this post (which was submitted as "IBM Cloud down as well as their status page which looks to be hosted there") could at some point have been "IBM Cloud down as well as their status page which looks to be hosted there as well as the forum where people post these things which also looks to be hosted there".
If it was a BGP issue, it's not a problem of where the status page is hosted but instead that you just can't get to it via that name no matter where it's hosted, right?
edit: It's possible that you could take out an entire TLD and make it impossible to resolve domains on that TLD once all the cached records expire. But that kind of targeted attack would not be possible with a BGP error, unless it was a very specifically crafted BGP error happening over a very long period of time (weeks-months-years depending on the record TTLs).