I think that the recent dip wouldn't be much in comparison to what could happen if BIP91 failed and then the issue of SegWit and scaling is left onto the more aggressive (and potentially distractive thanks to its divisive nature) BIP 148.
BIP 148 won't matter too much.
A lot of supporters of larger blocks might start moving to Bitcoin Cash though. I wonder what the value of that will be a month or two on from August 1st.