Tokenization typically means that a third party keeps an association table, though it is possible to generate tokens cryptographically. Homomorphic encryption is something different again, though you could call this structure-preserving pseudonymization homomorphic as it preserves certain structural properties of the input data. It does not provide the same security guarantees as FHE though as the structure preservation weakens the encryption. For pseudonymization this is a tradeoff that can be worthwhile though.