来源是最新一篇Riot dev的Blog文
https://na.leagueoflegends.com/en-us/news/dev/dev-updates-on-2020-ranked-matchmaking/
Promo Series:oward the goal ofmproving progression satisfaction and skill expression in our systems, it's looking likely that we’ll be removing inter-division promotions to reduce frustration of seemingly hitting a wall whenou knowou’ve been playing well. This means we'll also need to look at inter-division demotion protections to make sure that players are able to get where they should be in both directions without false limitations.
其中一段讲明他们有意将晋级战移除，以减少玩家“就算总体来说玩到很好，也有机会撞到铁板”的挫败感。
当然原文没有一口咬定，但英文looking likely原本就有“除非出现重大变量，不然都会发生”的语感
删除原因我也很有感呢...我朋友最近20场积分16胜4败，其中三败就是连胜上白金BO5然后0-3直接下去。