No, the entire Donbas most certainly did not do that because most people who live in it are not ethnic Russians. It's clear that you don't understand that Donbas is
not the same thing as the two self-proclaimed Russian republics in the eastern
part of Donbas.
Many ethnic Ukrainians speak Russian as their first language, but they identify as ethnic Ukrainians, not as ethnic Russians. Putin doesn't get to call them Russians if they say they are Ukrainians. Get it? Are the Irish, the Welsh & the Scottish actually English because most of them speak only English? No, & no sane English person would claim otherwise.