Is the additional load going to be handled with more caching layers?
Yup! This is the easy scaling issue: unauthenticated users will get a cached response that isn't dynamically personalized for them. But the TTL will be low so it's still pretty real-timey.
That includes embeddable versions that look so fresh and cool that all medias want to include them in their articles even if we don't say anything interesting, right?