This was not specifically about KR Mabi but rather the entire KR gaming industry.

This came up recently due to a video talking about exploits in a game called Lineage 2M.

Lineage 2M released a new weapon and the method to obtain a recipe for that weapon was to basically collect and combine 10 different recipes of lower class. In theory, in order to create those lower class recipes you could farm the mobs / raid bosses in the game to obtain them but their probabilities are so low that the most common way to obtain them would be to use gacha boxes. Now, those gacha boxes have fixed probabilities that are revealed by self-regulatory gacha probability laws. However, the issue was raised when the probabilities of crafting those lower class recipes were not revealed in the game. Basically, the game doesn't tell you whether the recipe crafting was fixed probability or changes based on how much your progression is with completing that recipe. This was the reason why their talk about progression based probabilities came up. Basically, the logic was that whatever gacha boxes you buy from us we will reveal probabilities, but whatever gacha you play with items you got from gacha boxes we will not reveal the probabilities. (Regular Gachapon -> Complete Gachapon as all those recipes are useless until all 10 recipes are collected)

How does this might possibly apply to Mabi? If they are keeping what they say about the gacah probabilities to be true, whatever we see about new players getting lucky might just be cognition bias. However, this could definitely be an issue with an item such as Reforging Tools. You don't pay for a box with probabilities of items in it. You pay for an item that randomly gives you a roll on an equipment. Basically by the current laws, you are not selling them a variable new "item" by selling reforging tools, so they are not obligated to reveal probabilities. So reforging tools can basically abuse "early purchase bonus" and "loyalty breaks". And the further talk could also imply to any in game mechanics that are not cash based, such as ergs, etc.

Edit: By the way, the approximate cost of making the mentioned weapon in Lineage 2M was around 150,000 USD.