WWE does it all the time. Half of the midcarders in WWE at the moment have had major title wins/feuds/matches and then de-pushed completely afterwards. And pretty much all of them had a chance to be big stars:
Alex Riley (got a big win over Miz, was over as hell....then dropped off the face of the Earth)
Daniel Bryan (won MITB and has done nothing until now)
Dolph Ziggler (won the world title this year, only to do absolutely nothing when his storyline with Edge ended and he got "fired" from SmackDown)
Drew McIntyre (won the IC title, touted as the future of WWE - now he's losing almost every match on Superstars (!) and can't get on Raw or SD to save his life)
Jack Swagger (won MITB out of nowhere, won the world title, then lost it after 3 months and proceeded to do nothing until WM)
John Morrison (where do we start....over as hell, gets to the final of KOTR, wins No.1 Contender match at TLC, loses in a great match to Miz, impressive Rumble showing, impressive EC performance....then WM27 comes and I think we know the rest of the story)
Wade Barrett (Gets major heat as the leader of Nexus, then he gets replaced by Punk and pretty much does nothing for the next 8 months except winning the IC title which he loses to Ezekiel)
And of course the aforementioned Kofi Kingston. WWE does it all the time. Pretty much all the guys I listed above could be main eventers right now if WWE hadn't decided to do nothing with them.