Why should diff rise after the halving ?
I think that many of the miners turned off, if the BTC price stays the same or decreases.
Same thoughts here! Many old running S3 + S5 are going to be shut-down after the halving and the diff will stay or decrease a little for some time. Hopefully the bitcoin price keeps on rising instead!
However, as people begin replacing S7's with S9's, those S7's will be sold to people turning off S3/S5...