What does 小时级发射 refer to in 该型火箭具有“一箭多星”发射能力、小时级发射等多项优点?
It means quick-reaction launch.
How I came to this conclusion:

The article you linked has some sort of quote from the rocket designer 彭昆雅, whose paragraph of explanation concludes with 大幅缩短了发射链条，提高发射效率和效益。So the purpose of the rocket is to &quot;enormously reduce the launch chain and improve the launch efficiency and effectiveness&quot;. To improve the deployment time.

The Wikipedia page in Chinese about the Long March 11 states 长征十一号发射周期不超过72小时，最短发射时间在24小时以内

Switch to English, and after the first few sentences, which seem to echo your own translation, you see &quot;It was designed with the ability to launch on short notice [...]&quot;.

Check the source that Wikipedia has quoted, and you read &quot;The CZ-11 is developed [...] with the goal to provide a quick-reaction launch vehicle, which is easy to operate, cost-efficient to launch, can remain in storage for long period and reliably launch on short notice&quot;. There is consistency.

Another Wikipedia source, nasaspaceflight.com says &quot;It’s goal goal is to provide an easy to operate quick-reaction launch vehicle&quot;.

Finally Google for &quot;quick-reaction launch&quot; (quoted) and you'll find some additional references from non-Chinese websites about rocket capabilities.