There is no proof of that. However, 56% of people voted for him on the ballotage, so inevitably some of that 56% do belong to that unions.
Still he blatantly lied on who would pay for the much expected crisis, so this strike is well justified.
As a side note CGT, the workers confederacy calling for this strike, is historically peronist.
Is it possible that the current argetinian president, Javier Milei, was ancestrally named Mileikowsky also?