I'm sure, civilized world can demand answers from Kim Jong Un about working camps in his country, or Xi Jinping about concentration camps for Uighurs with the same probability of success.

Dictators don't care what people outside their dictatorship think and do, unless it possesses direct threat to their power. Russia has nukes and seems do not care about sanctions (I mean, starving people without access to medications is not a reason to care for Putin), so Merkel would unlikely receive any explanation from Putin, he's to busy posing on a horse with a naked torso for Western magazines.