No, it's from a forum post very recently.
The post.
I'll translate the comments here.
[ë§ŒëŒë¦°]ë³¶ìŒìžë¦¬: Just another common bullshit from miscellaneous posts area (similar to Bean Rua in MabiNation, except people also post Mabi related things like recent accomplishments, etc)
[하프]모모: I posted a comment but deleted it. I did hear that at dan 3, you do get some stat improvement, but it was more of a rumor. And specifically, the Bolt spells. It was just a thing that I heard on the side... so I can't really say for sure.
[하프]루비스코: I'll get people that can look into the files.
Now we just need to wait.
Also worth pointing out that the OP is from the Wolf server from the KR servers (울프서버), which is known as a 초딩 서버 by many people, or in English terms, child server, to note the immaturity, unreliability, ill-manners, etc, of the players (though this is just a generalization and obviously every player is different), which makes sense because among the origninal servers (Harp, Golem, Lute, Wolf, Bear [not in service] and Mandolin), Wolf and Lute were the newer servers and were the servers that allowed youngest of the bunch to join because the servers had age limit (for example, Harp was 18+). Wolf was the server I played in when I played in KR server.
Another thing to pin point to are the stats. With the supposed 40 max damage bonus instead of 15 as the dan 3 "reward", the guy at 1467 dex has 975 max. Now I know that 975 max isn't very low for many people, but when you take into account that at 1.5k dex, he would have 988 max with a 40 max damage giving skill, that's not very high especially considering he's using a Bhafel Combo. With that amount of supposed max added into dan 3, and with Korean players generally more invested into gears, it's completely reasonable to surpass 1k easily, when NA players like me are able to do so easily.
tl;dr The flaw with the screenie is that the OP is from a generally negatively viewed server and his max damage is way too low for how much max damage the supposed dan 3 gives and how much gear he most likely would have invested.
Like you said, regional difference is a thing to take into account, but I seriously doubt this is the case. Looks like a fluke to me.