Alrighty, now that the community wants to start making 10-bit H.264 (a.k.a High 10 Profile [Hi10P]) encoding the norm, it means that the audience will need to start updating their codecs (or players), or be forced to contend with major artifacts in their videos.
Supposedly capable of better compression, yet improving on the video quality, so in theory nothing will be compromised. You’ll probably not see a huge reduction in video size, but it’ll probably be noticeable if you compare the sizes of entire series.
Of course, it’s only going to slow down the already miserable pace of the mainstream adoption of the .mkv format, so just expect to need to continue encoding into .mp4 to play on external video players for a while to come.
It’s time to upgrade.