Apple has no LTE modems to begin with. Intel sucks though, better get a Sierra card (Qualcomm).
They do expect you to stay within the Apple ecosystem, and it works surprisingly well if you can live with it. It severely limits choice - and won't work for everyone.
Which is the same as an embedded modem. I know the US a third-world country when it comes to mobile networks, but why Apple assumes this is the case in other countries -- I don't get it.