Don't you think the big multipool miners are already offloading their stakes every day (or more frequently)? Just because they stop mining doesn't mean there's going to be a sudden off-loading. If anything I'd expect block halving to put an upward pressure on prices.
I have a feeling more then a few miners have not sold doge in speculation the halving will result in a jump in price. Afterwards they will sell because i think the halving is already priced in. Combine that with the fact that mining doge never results in good payouts for the hashing power. You always get less then the calcs tell you.. A lot less. So that means people are going to switch until diff goes down. So whatever coin(s) has enough ask depth will win the hashing power.