Are we talking about an Indian market 500 UCE Bullet fitted with a carburettor from the factory, here?
These were on sale alongside EFI models in India until a few years ago, but in this case the CV carbs used DO have TPS. There's no ECU in the fuel-injected sense, but the TPS is linked to the TCI ignition module on these bikes. Someone in India was marketing the TPS carbs as a kit to retro-fit to EFI models.
If the TCI is designed to work in tandem with a TPS, leave it alone, or fit the TCI off an earlier model, e.g the 500 AVL Machismo or Electra-X.
Royal Enfield (India) had three CDI ignition models in the range, the 2002 350 Electra, the A350 kick start Machismo and the 350 kick start Thunderbird, AFAIK the auto-advance was built into the CDI controller electronically, there's certainly no vacuum ignition control on these.
The AVL models came with CV carbs from the factory (apart from the Dell'Orto PHBHs fitted to early A350 Machismos) but no TPS, and definitely not on the after-market carburettors many of us are using.
A.