This is certainly a topic worth exploring, and I appreciate the fact that you have raised it up for discussion.  I agree with you on some points, but I disagree on a few others. First, I agree that high volatility today increases the forecast of future volatility. If you look at volatility models, like GARCH, and in simplistic terms, future volatility predictions are similar to a weighted average of historical volatility, with the most recent volatility observations receiving the most weight. But as you move out over time, the volatility forecast moves closer to the historical volatility average. It is not a random walk model where the best prediction of future volatility is the volatility today. But my volatility prediction for tomorrow is higher if volatility received a large positive shock today.  Now, my risk tolerance, assuming I am an average 401K investor, who deposits a bit each month into a retirement account, is not based on today’s volatility. It is based on my forecast of future volatility over the life of my holding period. If I am young, today’s volatility does very little to change my future volatility prediction. And if I am old, while it does change my future volatility prediction by a greater amount, presumably I have been moving out of risky assets over time, so any adjustment I make into less risky assets would be small.  There is certainly an argument to be made that because many investors don’t have the discipline required to buy and hold through periods of high volatility, it makes sense for them to avoid stocks rather than buy at the top and sell at the bottom, but if one is following the traditional 401K risk-adjusted-for-age advice, then high volatility today shouldn’t require significant portfolio rebalancing.
If markets can go up a lot, they can go down a lot. And when an asset class gets more volatile, it gets riskier. Your risk appetite hasn't changed over the past couple of months, so your appetite for stocks should really have gone down.