Yes, this happened to me.
Will_Wam has responded to me before. Here is a way you can get him to respond to YOU! Go to [removed by checking terms of service] to find out how many messages he has. If it is less than 90, he should be checking his messages. Then, say on his profile "Hi @Will_Wam!" After that, he has about a 25-90% chance of responding. If he does, then reply to him as soon as physically possible with your question.