"Slippery slope" is, by itself, a mechanism. It means exactly what you're describing in your last paragraph, except it does not require someone explicitly planning the progression.
"Spreading out the implementation..." does not improve the argument because it's just restating the definition of "slippery slope". The statement that Netflix has some "evil master plan" is an assertion without proof and doesn't add anything to the argument, either.
The premise that Netflix is acting with mallace could be false or true. If that premise is stated and false, then the argument is valid yet unsound because it has a false premise. Valid meaning, the conclusion would follow from the premises if all of them were true.
If you remove discussion of the mechanism from the argument, so that it reads like the arguments stated in the first and second paragraphs, then the argument is invalid because the conclusion does not follow from the premises. That's what a fallacy is.
"Slippery slope" is, by itself, a mechanism. It means exactly what you're describing in your last paragraph, except it does not require someone explicitly planning the progression.
"Spreading out the implementation..." does not improve the argument because it's just restating the definition of "slippery slope". The statement that Netflix has some "evil master plan" is an assertion without proof and doesn't add anything to the argument, either.