I don't think that's "sure" at all. For one thing, only Python code directly calling Python has that option in the first place, often there is another layer of indirection, e.g., Python code which executes a shell script, which itself invokes Python, etc.
IME it is common to see a process tree with multiple invocations of Python in a ancestor relationship with other processes in between.
In rare cases, programs might also care about the VIRTUAL_ENV environment variable set by the activate script, and activation may also temporarily clear out any existing PYTHONHOME (a rarely used override for the location of the standard library). But yes, in general you can just run the executable directly.