I think he could given some training. He would be clearly good at:
Pole vault: 6.25m (1314 pts)
100m dash: ran 10.57 in HS, assume he could probably run 10.2 today? (1047 pts)
Long jump: jumped 7.15m in HS, probably could jump 7.75m today? (997 pts)
110m hurdles: given 10.2 100m, maybe could run 13.6? (1027 pts)
400m: ran 23.03 for 200m in HS, so maybe today he could run 48 for 400 (909 pts)
That puts him at 5294 points before the last 5 events. So he'd need to get 3833 points to set the world record, or only 766 average. That works out to:
High jump: 1.96m
1500m: 4:27
Shot put: 14.26m
Javelin: 61.84m
Discus: 44.93m
I am pretty confident he could manage the high jump, could probably even do better than that. The 1500 isn't a crazy time. I don't know much about the throwing events, that would probably be his weakest spot but most of the actual decathlon athletes beat 766.
And to win gold this year he would have only needed 8800, over 300 less points. He's basically accomplished everything possible in pole vault, maybe he'll go win the decathlon now.