x570 boards will be packing VRM - think what Gigabyte and MSI have done with z390 and left asus trailing .
and again, if your gunning for ryzen 2***, i'd wait for 4*** series to replace it 2020. your spending a lot of cash to replace a chip in 6 months time . Most users didn't move from ryzen 1*** to 2*** as it was optimisation , which 4*** series should be over 3***
if you know your going to be aiming for 12 core ryzen in the next 2 years, would be x470 board, and a flasgship at that . yes ryzen 7 has low TDP and unlike intel don't taste wattage as base level but at boost, when you manually overclock all cores the TDP does shoot up . same should be said for 7nm ryzen. Key to watch 7nm Vega release and see power draw it uses whilst being on the smaller node but increasing speed etc