Watermarking just alters the pseudorandom number generator. If "I like turtles" was previously the response to your prompt with probability 100%, it will still be so. This is why watermarking is only effective for long strings of text

It's like the sudden change of a language style and its verbosity didn't happen recently.

To random words you pick and provide a sufficient amount of text to vary with random number without losing its meaning you need a text with high entropy.

Nothing about watermarking would require padding the response length with pseudo-intelligible Claudese. Regular filler would work fine.

Also, it would probably provide higher entropy to write normal human-sounding English instead of reusing a repetitive grab bag of load-bearing phrases. This theory doesn't really make any sense.