This was immediately followed by the pilot's "Request high speed climb" and was answered immediately with "Approved request".
In the US, it's only a courtesy request, except for a very few airports (e.g., ORD) where there is a specific 250 KIAS speed limit that overrides the 'minimum clean speed' guidance.
However, Eva likely makes the request routinely because Taipei is also an airport with a specific 250 KIAS restriction.