From what I've read, he doesn't really practice, so there is no reason for him to be in a rush except for maybe learning whatever system he's going into and he's a veteran so that's probably not a big worry. He's just waiting for whoever is the best situation/most money. I could see it stretching into the preseason, idk about into midseason but it's possible
He probably has a couple offers in hand and is in no rush to sign. I really doubt he foregoes a salary in the hopes that a top receiver goes down mid season on a team that’s willing to pay up.
If we wanted to get a maximum paycheck, he would be with the Patriots or the Titans by now. At this point, I think he is just looking to avoid the entirety of the offseason program, and perhaps in the process a major WR1 will go down and provide him with another option.