He is talking late June early July. There is a lot of time for melting between now and then. The main thing is that the snow is walkable that time of year if it remains. I really like to do Pohono Trail before Glacier Point opens because it is so nice to not have the hordes of cars and people.

As for North Rim, with facing the sun, it will melt off quite well once it gets started. I did it end of April (before the drought) and it was OK. Yes, solid snow on upper Snow Creek, but it was fine walking- tracks showing that plenty of people had done it.

Yosemite is always my "go-to" May-mid June backpacking location. The waterfalls are at their peak. Just deal with a bit of snow, and it is fantastic. There are so many fine 2-4 day loops from the Valley. And the Valley itself is in its prime.