I was hoping for a new voice, but our wide receivers are going to succeed or fail ultimately based on talent, the QB throwing to them, and how well Van Pelt gets things up to speed. The results the last two years (if you adjust for the talent of the receivers) have been mixed at best, and how much of that blame to put on Brown versus Patricia/O'Brien and Mac/Zappe is up for debate:
Meyers progressed well
Bourne (for 2 out of 3 years) was very good, and the year he wasn't I don't think was due to a position coach.
Thornton, Parker, JuJu were all disappointments.
Douglas had good statistical success, but had issues with some of the technical aspects of the position. But he's a rookie, so I consider this neutral on Brown's resume.
I don't think it's fair to judge anyone on players like Boutte or Reagor.
EDIT: N'Keal Harry is a major knock on him as well, though there's been enough discourse around that decision in general that I don't think he should take ALL of that blame. It's not like Harry went off as soon as he got another coach.