2 Months ago Tencent puts up Job listings for their Chinese server of VALORANT Mobile and this went silent until the past few weeks they start updating the job description again, this time during Champions
I don't think Riot is saving announcement for Champions Finals, just a fun coincidence in timing.
as a side note: in VALM You switch sides after 7 rounds instead of 12, and you need 8 instead of 13 rounds to win the game