GitHub Pages only has a soft limit. As their documentation say:
> If your site exceeds these usage quotas, we may not be able to serve your site, or you may receive a polite email from GitHub Support or GitHub Premium Support suggesting strategies for reducing your site's impact on our servers, including putting a third-party content distribution network (CDN) in front of your site, making use of other GitHub features such as releases, or moving to a different hosting service that might better fit your needs.
I expect one-time hitting front page of HN or Reddit is something they won't frown on too much, whereas constantly hitting that cap on an ongoing basis is going to raise many more eyebrows.
> If your site exceeds these usage quotas, we may not be able to serve your site, or you may receive a polite email from GitHub Support or GitHub Premium Support suggesting strategies for reducing your site's impact on our servers, including putting a third-party content distribution network (CDN) in front of your site, making use of other GitHub features such as releases, or moving to a different hosting service that might better fit your needs.
I expect one-time hitting front page of HN or Reddit is something they won't frown on too much, whereas constantly hitting that cap on an ongoing basis is going to raise many more eyebrows.