The BNB coin had already fallen to around 270 price mark when the news bout SEC investigating Binance broke out. Even though they hover around 280-290 right now, I said it is still pretty bearish, won't be rock bottom as you said but... I think everyone should reduce the amount of BNB they're holding right now just to be safe. If it falls again since bearish or bad news about the SEC investigation, you can buy it back.
I think I kind of agree with your advice on this one, because in a judicial system of this nature, things tend to go unpredictable at times, periods like this and cases associated with fraud are never an easy one to come out from uncut, though nothing is completely impossible since it’s Binance we are talking about – the large exchange market there is.
But to be on a safer side, the volume of BNB coins accumulated by a person in Binance, at this point should be reduced, because it’s likely that the price of the coin will be affected slightly by any negative outcome or verdict that doesn’t favor Binance.