Pycom as released the first NB-IoT firmware:
unfortunately support for Huawei based networks such as T-Mobile isn’t working yet. Also we need UDP passthrough support from the network (coming before Summer as Afzal said) because we only support IP operation.
We’re only limited by what Sequans - the modem chipset manufacturer - can offer us so once they supply a working firmware for Huawei and either Sequans supports CDP or T-Mobile supports UDP Passthrough mode we’ll be able to support this amazing network.
I have to say I feel bad because of all the NB-IoT networks I have tested T-Mobile NL has been the best so far - great service uptime, coverage even during trial phase and of course great support team. I really wish Pycom could support it sooner.