I'm quoting straight from the documentation:
Note the following size limitations for the response:
The outputSpeech response cannot exceed 8000 characters.
All of the text included in a card cannot exceed 8000 characters. This includes the title, content, text, and image URLs.
An image URL (smallImageUrl or largeImageUrl) cannot exceed 2000 characters.
The token included in an audioItem.stream for the AudioPlayer.Play directive cannot exceed 1024 characters.
The url included in an audioItem.stream for the AudioPlayer.Play directive cannot exceed 8000 characters.
The total size of your response cannot exceed 24 kilobytes.
If your response exceeds these limits, the Alexa service returns an error.
So, the limit you are asking is still valid.