Here's a list of champions (displays best on desktop) from the last seven years with the current weight classes plus 2011 with the old weights (I may have misspelled a name or school)
As mentioned, the weight class changes make it challenging to create a 16-person bracket. The old 130-135-140 weight classes now are 132-138 and in the upper weights the old 189-215 is now 182-195-220.
Taking the last seven, you can run them through an 8-man bracket with the top seed getting a bye. Someone with far more knowledge would have to seed them.
Weight Class
106
113
120
126
132
138
145
152
160
170
182
195
220
285
2018
Jacob Moran, Portage (Jr., 34-2)
Brayden Curtis, Yorktown (Jr., 40-0)
Hunter Watts, Jimtown (Jr., 44-1)
Asa Garcia, Avon (Jr., 39-4)
Graham Rooks, Columbus East (Sr., 48-0)
Kris Rumph, Portage (Sr., 32-4)
Jordan Slivka, Cathedral (Jr., 43-3)
Brayton Lee, Brownsburg (Sr., 34-0)
Nick South, Columbus East (Jr., 48-1)
Noah Warren, Perry Meridian (Sr., 46-1)
Conner Graber, Northridge (Sr., 48-1)
Lucas Davison, Chesterton (Sr., 52-0)
Mason Parris, Lawrenceburg (Sr., 47-0)
Eli Pokorney, Chesterton (Jr., 42-0)
2017
Brayden Curtis, Yorktown (So., 43-0)
Alec Viduya, Roncalli (Fr., 47-2)
Cayden Rooks, Columbus East (So., 46-1)
Alec White, New Palestine (Sr., 39-1)
Breyden Bailey, Cathedral (Sr., 42-1)
Brendan Black, Hobart (Sr., 30-1)
Brayton Lee, Brownsburg (Jr., 46-0)
Joe Lee, Mater Dei (Jr., 36-0)
Brad Laughlin, Yorktown (Sr., 46-1)
Eli Stock, Monrovia (Sr., 41-2)
Jacob Gray, Delta (Sr., 42-2)
Andrew Davison, Chesterton (Sr., 42-0)
Mason Parris, Lawrenceburg (Sr., 47-0)
Evan Ellis, Eastern (Sr., 46-0)
2016
Asa Garcia, Avon (Fr., 36-6)
Colton Cummings, Lowell (Jr., 46-0)
Drew HIldebrandt, Penn (Sr., 46-1)
Brock Hudkins, Danville (Sr., 47-0)
Chad Red, New Palestine (Sr., 44-0)
Brayton Lee, Brownsburg (So., 43-0)
Joe Lee, Mater Dei (So., 32-2)
Trent Pruitt, Warren Central (Jr., 45-2)
Jacob Covaciu, Merriville (Sr., 42-0)
Drew Hughes, Lowell (Sr., 47-0)
Blake Rypel, Cathedral (Sr., 45-0)
Jake Kleimola, Lake Central (Sr., 43-1)
Mason Parris, Lawrenceburg (Sr., 47-0)
Shawn Streck, Merrillville (Sr., 45-0)
2015
Colton Cummings, Lowell (So., 45-1)
Garrett Pepple, East Noble (Sr., 46-0)
Brock Hudkins, Danville (Jr., 33-0)
Chad Red, New Palestine (Jr., 47-0)
Nick Lee, Mater Dei (So., 35-0)
Tommy Cash, Lawrence North (Sr., 45-2)
Jacob Covaciu, Merriville (Jr., 44-1)
Tommy Forte, Mishawaka (Sr., 37-0)
Drew Hughes, Lowell (Jr., 44-0)
Dylan Lydy, Ben Davis (Sr., 46-0)
Chase Osborn, Penn (Sr., 39-0)
Blake Rypel, Cathedral (Jr., 46-0)
Kobe Woods, Penn (Jr., 44-0)
Shawn Streck, Merrillville (Sr., 45-0)
2014
Jeremiah Reitz, Griffith (Fr., 45-1)
DJ Smith, Franklin Community (Sr., 39-1)
Chad Red, New Palestine (So., 44-0)
Stevan Micic, Hanover Central (Sr., 42-0)
Deondre Wilson, Warren Central (Sr., 39-0)
Tommy Cash, Lawrence North (Sr., 45-2)
Cody LeCount, Perry Meridian (Sr., 44-0)
Brendon Kelley, Evansville Central (Sr., 50-0)
Rhett Hiestand, Yorktown (Sr., 47-2)
Jacob Stevenson, Franklin Community (Jr., 40-1)
Damien Chambers, Edgewood (Sr., 44-1)
Katrell Moss, Warren Central (Sr., 31-2)
Gelen Robinson, Lake Central (Sr., 52-0)
Wesley Bernard, Cathedral (Sr., 49-0)
2013
Chad Red, New Palestine (Fr., 48-0)
Stevan Micic, Hanover Central (Jr., 48-0)
Deondre Wilson, Warren Central (Jr., 38-0)
Nick Crume, Jimtown (Sr., 38-0)
Cody LeCount, Perry Meridian (Jr., 40-0)
Tommy Forte, Mishawaka (So., 46-0)
Neal Malloy, Danville (Sr., 43-0)
Josh Farrell, Greenfield Central (Sr., 48-0)
Riley McClurg, Perry Meridian (Sr., 37-3)
Bobby Steveson, Merriville (So., 39-0)
Matt Hurford, Culver Community (Sr., 47-0)
Mitch Sliga, Fishers (Sr., 49-0)
Gelen Robinson, Lake Central (Sr., 52-0)
Donte Winfield, Perry Meridian (Sr., 41-2)
2012
Stevan Micic, Hanover Central (So., 47-0)
Jarred Brooks, Warsaw (Sr., 35-0)
Paul Petrov, Hanover Central (Sr., 47-0)
Kyle Ayersman, Lake Central (Sr., 52-0)
Jared McKinley, Perry Meridian (Sr., 48-1)
Devon Jackson, Yorktown (Sr., 52-0)
Jason Tsirtsis, Crown Point (Sr., 42-0)
Isaiah Bradley, Muncie South (Jr., 44-0)
Brian Harvey, Cathedral (Sr., 47-0)
Sean Mappes, Center Grove (Sr. 46-0)
Tanner Lynde, Delphi (Sr., 52-0)
Mitch Sliga, Fishers (Jr., 49-0)
Tyler Kral, Crown Point (Sr., 41-2)
Abraham Hall, Bremen (Sr., 50-0)