Nerve damage is part of the territory. I've not heard anyone complain about loss of feeling to chin/lower lip. Upper lip is rare but does happen. Palate is rare and more annoying because your burn yourself. Gums is fairly common but people don't seem to care. The more surgery you get, the greater the chances of nerve damage. Sliding genio, for example, increases the odds of permanent nerve loss to lip/chin by 40%, though figures vary. The greater the movements the greater the chance of loss. Loss is not black and white, typically it's patch with some areas lost and some unaffected and usually described as a range, maybe hot/cold sensation but not touch for example. No way to avoid damage to the maxilla, it has to be cut but the graft material used can affect how well it heals. Age may be a risk factor but some studies show it only affects the rate of recovery not the chances. Over 40 it is at least believe that changes are harder to acclimate too but it's a psyhcological thing. Bottom line: it'll happen to some degree and you'll most likely adjust to it easily, especially knowing there's a very good chance most of it will come back. And if it doesn't, you'll likely be used to it by then.
