The concern for the Democratic Party is valid in terms of the possibility that Bloomberg-types can create a socially progressive but still oligarchical juggernaut that forever maintains power simply by being the better option to the Theocrat/conservative but also oligarchical party.
I think the eventual result of that is a hybrid populist party pulling from less-socially-conservative former Trump supporters and the far left. For me, a two-party system of a socially progressive Wall Street party vs. a socially progressive socialist/populist party is far preferable to the status quo, even if it takes a few more elections to get there.