There will be several concerns to use eMTC for such application.
1. High operational cost. though have not seen any plan rolling out from telco, it is anticipated higher subscription cost than NB-IoT, and sure higher than other LPWA choices.
2. Correct me if I am wrong, LTE-M1 will share the same spectrum and throughput with legacy 4G broadband data, that means if in particular time and place, 4G data traffic suffer congestion, IoT traffic will suffer big latency, which is killer concern for asset tracking application.
3. Privacy concern. owner may not want any asset information going through a public network.
that is why private network like LoRaWAN was first thought.