I'm sorry to say mate but this sounds a bit tinfoil to me. It makes perfect sense to give free spins absolutely yes, there are multiple reasons for this. It is in casinos interest to engage players, make them feel noticed, make them try new games, people granted free spins might get excited and make a deposit etc. After all the fee spins already made you log in so it is easier. The impact (if there is any) to players total RTP is completely secondary if not insignificant from the casinos point of view. Keep in mind that many of the recreational players don't even know what RTP is yet alone care about it.