NFL Connections #90, Answers
The full solution: all four groups and the 16 names, sorted from the easiest group to the trickiest.
Tight ends of today
Travis Kelce, George Kittle, Mark Andrews, T.J. Hockenson
Tight ends of the 2000s
Tony Gonzalez, Antonio Gates, Jason Witten, Rob Gronkowski
Hall of Fame tight ends (classic)
Mike Ditka, John Mackey, Kellen Winslow, Ozzie Newsome
Pass-catching tight ends
Shannon Sharpe, Dallas Clark, Jeremy Shockey, Greg Olsen