Hey Bloggs, have they improved the system lateral tracking of your GPS approaches?
Can't have you landing on the taxiway.
Also LNAV/VNAV either need temp compensation capability or a temp limit. In Aus, the temp limit is not very "limiting" so would be the easiest option (and the only option for some systems). The problem with ISA+ temps is the Vnav invariably brings you in high on profile, necessitating a destabilising dip once visual.
ISA - temps bring you in low, hence the need for temp compensation to keep away from the hard bits beneath you.
I guess if the airport doesn't have an AWIS, it won't be getting an LNAV/VNAV approach.