Generally, but with a lot of exceptions and weirdness. For example, my OnePlus 6 is not supported, but if I modify my IMEI and APN those "impossible" features like VoLTE suddenly start working. Before they stopped automatic activation, I could put my SIM out of a supported phone, put it in an unsupported one, and those features would work for between fifteen minutes and a couple of hours.

On the other hand, some handsets that are blatantly missing LTE bands are on the whitelist, such as the Chinese Oneplus 8T.