I thought it had been established from the NTSB that VS mode was engaged not FLCH.
Exactly what was
not established.
The NTSB Chair is very clear about what she is passing on, and not to draw inferences beyond that.
IIRC she said that one Flt Crew member recalled, at ~4000 (?)', they were in V/S ~1500'/m. It was purely the interview recollection at one point in time from 1 person / interview.
Very different from a (theoretical/future) NTSB report aspect that the FDR revealed the ATHR mode active/engaged at the time the speed fell below target.
I think the NTSB chair is doing an excellent job is clarifying what she is saying... and I think we should do our best to honour that clarity.