I wouldn’t call it “using correct pronunciation”—the whole idea of hypercorrection is that the result is not correct, because some perceived rule was mistakenly

I wouldn’t call it “using correct pronunciation”—the whole idea of hypercorrection is that the result is not correct, because some perceived rule was mistakenly over-applied, like in English * “He gave it to Sam and I”. (Plus I’m guessing that sound change happened pretty early on, because as far as I know, all Polish consonant clusters obey that rule of voicing & devoicing obstruents.)