Its only a matter of weeks now, days after the 1st of July. RSS feeds count as free access to the Reddit API and therefore unauthorized third party apps, so the're definitely be gone.
After the userbase has been conditioned to the fact that there isn't a 3rd party Reddit reader anymore, they will kill off old.reddit.com.
.webp? Oh great, I get to install Homebrew, search for some package to convert it into a PNG, figure out the command line options and then finally I'll get an usable version of the image.
In case you're actually wondering, its: