There's a whole blog article written by Dario Amodei, literally linked from the text "pacing the frontier" - click that and read if you need more context and understanding. The first sentence in this press release is merely stating a fact about the timeline - this is Anthropic's first release since Amodei released the referenced article.

I think it's perfectly clear. It means improvements shouldn't simply advance as fast as possible and more specifically, it's a reference to a past statement of theirs to that effect. At that level of generality it's as clear as it needs to be.

I would say the burden is on you to explain why an offhand reference to a previous press release in an executive summary is a context where it's reasonable to expect it to settle the question to the degree of detail you're demanding.

“Pacing the frontier” is similar to the role of a “pace car” in racing.

From https://en.wikipedia.org/wiki/Safety_car

> In motorsport, a safety car, or a pace car, is a car that limits the speed of competing cars or motorcycles on a racetrack in the case of a caution period, such as an obstruction on the track or bad weather.