That is a safety message that was implemented in 101 release. It is a safe guard to warn you that Niantic might be on you due to your current activity. However, this is my own assumption and I believe we all would want to be safe than sorry so a bit extra careful seems to be reasonable.
Honestly, my account received this message a few times and now all my pokemons are fleeing..... well guess what, I will wait 12 hours and follow their instructions. 12 hours may seem long but it would have taken me A LOT LONGER to get to my current status if I DID NOT bot.