Not sure if covered before, here or else where, if so, link me. But the bombs dropped in 2077. Fallout 4 emerges 200 years later as the only survivor(per E3 showing). Making it 2277.
The Lone Wanderer(fallout 3). Was also "active/set" in 2277. The voice actor for 3 dog posted this back on Jan 8, 2013. "To all my Fallout3 and ThreeDog fans: There may be more of the Dog coming! Fingers crossed!".
So timeline wise, 3 dog could possibly be heard in Fallout 4. Though the distance between the DC "wasteland" and Boston are over 400 miles apart.
*edit* just read through his twitter, he said this "Dear Fallout Friends, to ease your minds as of today I am not a part of #4. Should that change it will be a secret I will honor. "
It is interesting they set fallout 3 and 4 in the same year.