Actually, everyone wants all bands ready, including mmWave. These should be the bands available in the upcoming 5G auctions according to Esmail from OnlyTechmmwave will not be released by the next 5g auction do they?, so we have to wait for few years i guess for the mmwave to get deployed
n78, n257 and n258
They could lower the price of band b28/n28 and put it up in the auctions so eventually all 3 operators would buy 10MHz at base price. (There's just 30MHz available)