Hmm, I grabbed one of the links, hit "view source", searched for "atom" and "rss", and found: https://openai.com/blog/rss/

I haven't fed it into my RSS reader, which is on another machine, but, inspecting it with curl, it looks like RSS XML... does it not work for you?

It is a problem that the webpage doesn't give any visible sign that it supports RSS. That is unfortunately common; I don't know why they do that. Anyway, for what it's worth:

  # fish shell here, with an alias
  ~> for x in (P | tr -d ' '); echo $x (curl -sL $x | egrep -c -i 'rss|atom'); end 
  ... omitting the non-matches ...
  https://blog.close.com 1
  https://bloggingfordevs.com/blog 1
  https://discord.com/blog 1
  https://linktr.ee/blog 2
  https://openai.com/blog/openai-api 1
  https://segment.com/blog 2
  https://web.dev/blog 1
  https://www.linode.com/blog 4
  https://www.tradingview.com/blog/en 1