I believe there is a reason why Niantic choose to put this feature in now. Thinking about it for a bit, when new mechanics are added to the game, any game in general. People love using it when it firsts arrives. Sometimes developers do this for a reason, knowing of these statistics. We all know there should be an event starting here within a week or two. So why would Niantic release a patch with such a feature?
It has been heavily theorized that with the Holiday event, it will be very similar to the Halloween event. This means we can expect increased spawn for ice and possibly water type Pokemon, decreased distance needed for buddy candy, and that’s right… double candy. There has been “rumor” of other event bonuses but I’m going to focus on the double candy bonus for now.
Typically when updates as such, they hint towards future mechanics to expect. I have seen “game changing” updates and patches in every game I’ve ever played. With all of this being said, though not confirmed, I believe Niantic added this feature to force inexperienced and unsuspecting trainers to use the feature before the release of the event.
Yes, you can use it if you would like, but for those who are so close yet so far from completing the Pokedex. I would highly recommend you save Pokemon. At least the ones you are still trying to get the tedious last candies for. It’s not going to hurt anyone to save Pokemon. If this theory proves to be true, it may hurt players that transfer before hand.