I think that you, as the uploader, can actually decide on the codec to be used. A lot of YouTube appears to already be AV1.
I think a lot of Netflix as well, but it seems nothing in HDR yet.
by Liwei Guo, Ashwin Kumar Gopi Valliammal, Raymond Tam, Chris Pham, Agata Opalach, Weibo Ni
netflixtechblog.com
We always encode at the highest available source resolution and frame rate. For example, for titles where the source is 4K and high frame rate (HFR) such as “Formula 1: Drive to Survive”, we produce AV1 streams in 4K and HFR. This allows us to present the content exactly as creatively envisioned on devices and plans which support such high resolution and frame-rate playback.
All AV1 streams are encoded with 10 bit-depth even if AV1 Main Profile allows both 8 and 10 bit-depth. Almost all movies and TV shows are delivered to Netflix at 10 or higher bit-depth. Using 10-bit encoding can better preserve the creative intent and reduce the chances of artifacts (e.g., banding).
Dynamic optimization is used to adapt the recipe at the shot level and intelligently allocate bits. Streams on the Netflix service can easily be watched millions of times, and thus the optimization on the encoding side goes a long way in improving member experience. With dynamic optimization, we allocate more bits to more complex shots to meet Netflix’s high bar of visual quality, while encoding simple shots at the same high quality but with much fewer bits