There will be very few phones until H2 2019 but a handful are ready to trickle out. Qualcomm's demo phone made a call at a show in Hong Kong. They announced there will be phones from Xiaomi, OPPO, vivo, Sony, Motorola, Asus, HMD/Nokia, HTC/Google, and LG in 2019. Xiaomi is rumoured to announce a phone this week. Ericsson, Nokia, Huawei, Samsung, and ZTE claim their base stations are ready to go. Verizon is live, ready to serve tens of thousands. CEO Vestberg is frustrated because his vendors can't deliver the phones until June or July.
Unfortunately, no one can produce the chips in quantity today. 5G NR is so demanding that it requires absolutely the most advanced chip manufacturing. Qualcomm is ready with the X50 modem, a new small antenna, a remarkably small RF front end and a reference design.
Only TSMC, Samsung, and Intel can produce the necessary chips.