Caerphilly's flavour, the tang it has, is primarily due to it being a young cheese. If you age it out, the flavour profile will change, and mature, and become more like a cheddar type. So, the short time span is to get it at the appropriate point in the ripening process. I wouldn't be surprised if lancashire also has a tang when very young, but the salt levels and other bits would be off. Caerphilly is a bit salty, which works with the sour tang of a young cheese. The salting during the press is again, to get the salty profile, it can be a bit much and I often cut it back quite a bit, and just sprinkle a bit. I think it helps dry the rind just a bit faster, to trap more moisture internally, to help develop the tang in the flavour, but I'm not sure on that.
Remember, the different aging durations are to get a cheese to the point of maturation typical of that type of cheese (i.e. caerphilly, lancashire, vintage cheddar), it's not like it takes different amounts of time to get to the same place ; they all have different destinations, and see different points along the way. Some, like Goudas and cheddars, have multiple points of goodness, some peak and then go into unrecoverable decline, then free fall (i.e. you don't see a lot of "vintage Brie" for a reason).