Originally Posted by Govnor
It can be. I've heard the same for every other 0.5 jump as well!
This is the nature of a half point rating system where in theory a half point difference between opponents should result in a 6-0,6-0 match. This is the reason why a quarter point rating system seems attractive.
For example, someone right on the 3.5/4.0 boundary is going to be expected to beat the average 3.5 6-3,6-3 and lose to the average 4.0 6-3,6-3. In fact, they'd be the "pick" in any match against a 3.5 (that isn't themselves about to be moved up) and picked to lose in any 4.0 match (unless they get a 3.5 playing up).
Now, not every player is average and from what I've seen estimating dynamic ratings, an individual player's rating can vary a full half point from match to match so this hypothetical player won't necessarily lose every 4.0 match and win every 3.5 one, but that will be the result more often than not unless the player improves their game.