Because most VCL (including JP) have already started prior to the implementation of Group Pickems, we felt that rather to shoehorn the option mid-Split for them, we'd start Group Pickems in Split 2 for these VCLs to ensure a clean start.
It's not a matter of popularity or not. We want to try test this on as many VCLs as possible. Most likely VCL South Asia and Vietnam will be Pacific's own test. LATAM as well.