It's not that expensive to host old blog posts and they already host videos on YouTube... What's expensive in those operations is supporting new content and growth. Now they can wind it down and establish a fixed legacy system and eventually run it on autopilot with a small team in support roles.
And they'll keep updating contracts to sell ads for a defunct site? Seems doubtful. Past experience shows that the site is unlikely to stay up for the long haul.
You don't need to sell ads directly to Nike to make more than enough $$ to incentivize running an existing major content site, let alone pay for a small team to sufficently keep it running tech wise...
People just try and hack it constantly - as in, hundreds of automated hacking attempts per day, and when they succeed, they won't make obvious changes, they'll tweak things gently in a malignant way that won't be noticed for some time.
It's really not that complicated to manage cloudflare type Web app firewalls and shutdown content interfaces, both comment sections and admin panels, so there's no malleable auth areas to breach. And even if that happens a small team could easily handle run of the mill script kiddies and SEO schemes.