It has rc8 which was used between s20 and s21 of esea which was about half a year after that vid was posted, so it might be the one. If it's rc7 in the vid, I can't find it on page 1 on google and that's as much effort as I'm willing to put in
Edit: https://tf2maps.net/downloads/sunshine.47/history this one only has rc8 and 9 too, Phi's tftv post links to tf2maps and no other mirrors so ye, good luck if u need 7
Edit #2 I am your god https://www.mediafire.com/file/f7l49ckflvxqgcd/cp_sunshine_rc7.bsp.bz2/file
from https://www.teamfortress.tv/11931/cp-sunshine-5cp?page=16#468