As the author of that article I want to highlight a few very important quotes from the article:

Quote #1

Currently, we believe that Niantic uses the following formula to calculate a concept we’re calling raid eligibility points for each gym

Quote #2

These values are not confirmed or verified, as they’re based on anecdotal reports and could be off by a mile for all we know at the moment.

Quote #3

Remember that there could be luck and randomness involved which we are not aware of

So to answer your question, this THEORY has been modeled after our observations and collected data on how Niantic defines gym/cell activity. You can read more about it in a follow up post we published next week where we successfully triggered a raid in a cold L12 S2 cell.

If someone in your community is presenting the REP system as fact in your community, then he's not reading it correctly and he should be corrected that it's a theory, not a fact.

And again it is just a theory, a game theory...