There's absolutely no reason to reserve a permit for Meysan Lake.
There were 6 people on the trail on Friday and 6 people on the trail on Saturday.
Just show up at the interagency office in lone pine and pick up a permit.
Be aware that the flooding that was experienced in the Whitney area also affected the Meysan trail. There are numerous places where the trail has been washed out. Most of them just require more creative rock hopping to get to the trail again. There are a couple of places where it will take some effort to find the trail again. I recommend going up during the day. A couple of spots are a real challenge at night (because of the trail washouts).
Agreed, been up there many times in the summer and permits are no problem at all. Rangers have told me in the past that they hardly ever issue permits for that TH and I have mostly just seen a handful of dayhikers up there at the most.