HFT - yes. But longer-term investment (i.e. Buffett - or even with a horizon of a couple of years) is unlikely to be transformed soon - ML needs vast historical data, which is very slow to generate. Waiting 10 years only gives you 10 years of history, which is 5 non-overlapping 2-year forward returns, and maybe 1 or 2 economic/financial regimes.
This is also a problem with new datasets being generated - there is not nearly enough history available to test them or feed them to a ML system.
Furthermore, arguably, longer-term investment requires forward-looking modelling of scenarios, based on the kinds of inputs that were not seen in history. ML is not very applicable when you get big covariate shifts.
So I would say human financial analysts are not going anywhere, and any improvements would be relatively small and incremental.