-Did the changes are needed?
-Wasn't really needed, but if they want to go with 10bit then it's cool. I don't have any problems playing 10bit at all so it's even better for me since the file size is lower and it looks amazing.
-what should people who wants 8bit release do?
-I guess you can update your CCCP to the latest and go from there. Even my weak netbook (specs in the spoiler below) can play 10bit with no problems. If they really do have a good computer like they claimed they do and it still doesn't work then I guess theirs is as weak as mine or even weaker then.
-what should fansubs do for those people?
-Honestly, nothing. Learn to update codecs.
-which one that you prefer, 8 bit or 10 bit?
-10bit