Generally if cats are going to be part something in terms of breed, Siamese is one of the most common due to how popular a breed it is and how long it has been here (one of the oldest to be imported and bred here) - and there are certainly enough colourpoint strays and moggies around to indicate that Siamese (where that form of albinism originated) genes turn up all over the place.
So I would say if he has anything in him rather than being pure "natural" cat (ie. what we'd call Domestic Shorthair in his case, directly descended from the African Wild Cat) then having some Siamese in his ancestry would certainly be a good bet, he has a moderate wedge shaped face and almond shaped eyes, and you say he's very vocal - so it could be a possibility that he has a Siamese grandparent or great grandparent somewhere down the line.
Also the fact he is cream tabby and white rather than red tabby so a double whammy of the recessive dilute gene - now of course this can happen in domestic cats, but it is moderately rare, while many breeders of pedigree cats deliberately select for dilute colour modification (both my OSH boys were/are dilutes) and it is considerably more common in pedigree cats. That a cat has a more unusual colour doesn't necessarily mean it has some pedigree in it somewhere down the generations, but taking it into account along with other factors could lend weight to that, even if it alone wouldn't mean a lot.
(Dilute = pigment distributed in tiny spots on the hair shaft rather than solidly along it resulting in a faded or washed-out appearance of pigmented areas of fur - a genetically black cat will appear blue (ie. dark grey), a genetically brown/chocolate cat will appear lilac (ie. pale pinkish-grey), a genetically cinnamon cat will appear fawn (very pale and extremely rare in domestic non-pedigree cat population, not that common in pedigree cats either) and a genetically red cat will appear cream - which isn't
actually a cream colour, but a much paler red/ginger.)
Not that there is anything wrong with being a pure domesticated version of an African Wild Cat! Wonderful to have these little fierce predators so friendly in our homes, no matter how they came to be in their individual form