Not sure if it's been posted, but Schefter backed off on that report and Coleman said it wasn't true.
https://www.newyorkupstate.com/buffalo-bills/index.ssf/2018/08/corey_coleman_denies_weighing_options_before_joining_buffalo_bills.html
"Every day I wake up I feel like I have something to prove. This is a huge opportunity for me. I'm blessed to be here. I'm ready to rock with the Buffalo Bills."
A few hours after his original tweet, Schefter backtracked and said that multiple people, including Coleman, denied that the wide receiver balked on joining the Bills.
"Multiple people, including Coleman, say this is not true, and he did not balk about going to Buffalo," Schefter tweeted. "He found out Sunday night and drove to Rochester at 7 am Monday. Transaction was submitted to NFL at 1 pm. Coleman's a Bill."