No, changing the POW is the only way to break free from the influence of BTC favoring SHA256 miners. BCH will certainly fail without a pow algo change.
You can't ignore that having 1-2% of the total SHA256 hasrate is a systemic risk in itself and deters investments and usage.
...but... but... flippening?!? I was promised it would happen soon. Any minute now for certain. And besides, miners are our fwends. They would never hurt us, right?
The reasons as to why sticking with SHA256 is supposed to good for BCH seem to change as often as BTC change their narrative on what bitcoin was supposed to be.
Currently, BCH could still pull it off (there are enough community support to put enough CPU/GPU hashpower behind a new algo), but this window of opportunity is closing rapidly.