I took a quick look, and I saw flyuh scrimming with the SR roster in place of TiGG, and TSM playing with NiSMO and zander in place of Subroza and gMd.
will update if I find more
jcstani playing with fiziq, oderus, v1c, and thief
NAVI trialed both nukkye and jugi
Acend playing with CASE roxie instead of l1nk
chronicle played 2 deathmatches with derke, alfajer and boaster while being in the same party, this was 4 days ago
FNATIC played scrims with alt accounts:
"ppp" who played skye on bind, sage on icebox, breach on haven
"berserker4k" who played viper on bind
"fulltilt" who played sova on icebox and haven
Vitality ceNder playing scrims with alt accounts: "Beans on Toast", "xXxDESTROYERxXx", "piéton" "Vitality BOSSMAN" (bonecold)