Dependence on cellular service for everything seems unwise. Emergency low power informational stations on AM are not accessible, some with lights that say "Tune to xxxx AM if flashing."
That said, we've lived without AM or XM in the three for 2-1/2 years. Just had to get used to streaming stations stopping for no reason, even in areas of 5 LTE bars. We just sold our MS that had AM/FM/XM and I really miss XM on road trips, but we stopped using the MS on road trips in favor of the M3. So it's one of those things I grumble about but not a deal killer. AM is omitted in part due to all the RF noise EVs make, but I have no idea why XM was eliminated in the 3 and Y.