Nobody is saying wait until June 1st. Just a few days into FA is too early.
After the draft is the time to judge. Most roster work is done by then.
Actually like someone said players are now designated June 1st cuts ahead of that date so really you may think after the draft is best time to evaluate but all impact players are gone by end of 1st week of free agency.
I use Jordan sneakers as an example. People line up and wait days if not hours to get new edition because they know there are only a certain amount made and after the drop date they know they're out of luck unless they are desperate to pay 3 or 4 times the price from someone who paid $200 - $300 sale price.
The only guy worth noting available is Terron Armstead and he is waiting to see what NO does at QB first. Everyone else is either on decline or is flawed in some way (injury or inconsistency). Any guy cut after draft, see reasons above.