Something isn't quite making sense here....
IF that supposed ATC info is correct - that there seemed to be a sustained and abnormal acceleration - and this DOES seem to be borne out by the FR24 data, which seems to show increasing speed and increasing altitude then the aircraft flight path is NOT the same as Lion Air. Whatever various press releases seem to be claiming.
The Lion Air FDR data appears to show an aircraft exchanging kinetic and potential energy as it dives and accelerates, then climbs and slows , as it either is "MCASed" nose down or pulled back nose up alternately. The final DIVE is where the speed finally builds to by far the highest speed in the whole accident sequence.
ET doesn't do that. The FR24 data (unless there's something newer floating around) shows ground speed continuously increasing (albeit not at a constant rate) while the overall altitude trend is to climb - albeit with some instability. In other words, the ET aircraft seems to be gaining significant energy throughout the flight. No stab system malfunction can add total energy to the aircraft.
Dare I suggest something totally unrelated to MCAS, even though everyone has already jumped on that bandwagon (and grounded the aircraft). What about an uncontrolled high thrust event? Too much thrust, inability to reduce power from TO, something like that.