The lilac I asked about pruning last week has been pruned and looks better. But while pruning, the sun was shining through the leaves and I noticed all the leaves were spotted. New leaves look crinkled, and some tips of new growth have turned brown and been removed. I'm sure it's got bacterial blight.

Since it's done blooming here in zone 8, it seems too late to apply copper sulfate, which I read should be done during budding. My question is should I remove all the spotted leaves because they're going to turn brown anyway? What then happens with my naked lilac?