No. It's just this translator group that does that. They once claimed that they did so because they received "DMCA" claims but that's a complete load because DMCA takedowns are about copyright, which every single scanlation out there that's not creator-approved is guilty of regardless of whether or not they show cleavage.
What's likely actually at play here is that wherever they host their sites has stricter rules on content and they either don't get ad revenue or risk losing their hosting if they have anything too saucy. I wouldn't think that just cleavage would cross that line of unacceptable content and it's not like this group is doing manga that has full-blown exposed boobs. But whatever.
It's still less of an issue than them doing a shit, half-assed job of translating and then whining about losing money to aggregators or needing donations and commissions for their trash, non-proofread, borderline MTL level work.