I think this will not be the case anymore, those who got their RLB free had been selling it when the RLB market started uptrend last time. I think the RLB holders now has more patience and for sure they will be holding RLB for some time, and if RLB started to get bullish, the possibility of FOMO-ing is always there so it won't be surprising if we see another run that will break its current ATH. But for sure, dumping will happen when someone wants to cash out their profit.
Many investors who got their RLB through airdrop before probably sold their token already at the time Rollbit added the feature of buying and selling on the platform because it's already convenient. I know some who did this. The price is around $0.03 something at that time, quite cheap.
They didn't wait for a price growth and already take profit since they got their token for free.
It's understandable if investors are selling when there's an increase but if it is from airdrop, I think it's worth to wait since you already have nothing to lose. Those who have patience (even though they spend money to have RLB) are seeing the importance of holding because there's a chance to gain more if they wait further.