I suspect you mean a July 20th permit?
Yes, the main concern is if the level is too high in Muir Gorge to make it passable without going class 2-3 trying to bypass. All the other side creek crossings pale in comparison to the gorge.
I’ve been through when the gage was at 12 feet/800 CFM and there was about 1 foot from the trail in Muir Gorge to the river top. I estimate that it is passable when the gage above Hetch Hetchy is below ~12.5 feet (currently it’s ~14.5 feet) and the flow is below ~1,000 CFM (currently it’s ~1,800 CFM). Check the gage at https://waterdata.usgs.gov/ca/nwis/uv?11274790 .
Also check out this TR: http://www.highsierratopix.com/community/viewtopic.php?f=1&t=16159 .