Maybe I missed something since I don't get the chance to check all the league and site forum posts but I thought if a player's projected overall was decreasing after training camp their rookie year then they would continue decreasing until their actual rating caught up. Perry Carey is the only player I've seen who has changed his projected overall rating and is now increasing...is this a new update or an anomaly?
https://uro.myfootballnow.com/player/9908

So for me its like this most of the time if I get you right. The training camp kind of reveals the „real“ future rating which can be a big change in comparison to the initial one but doesn’t always have to be.

After that this changes only slightly in some cases or remain the same for me. The actual rating then rises up until it reaches the future rating depending on how many plays the player is getting on the field etc. For example a day one starter gets to that point in nearly one season while a backup can need much longer.

For me the future rating then only changes very rarely and slightly after later camps. And if the player gets into an older age of course. This also depends on the position. For exmaple WRs and RBs have a higher chance to decline already in year 9 while QBs, Kickers etc. often do later or even don‘t decline until they retire.

Hope that helped and didn‘t tell you everything you know already :D