Frostmourne new season affect on BG segmentation

Hello everyone, returning molten player here (played from 2010-2015). Am abit confused with the battleground segmentation which I have read about. Unfortunately, I've bought some furious gladiator gear (ilvl232) and my BGs since have been with the "high GS" group. My plan now is to gear up for the new season on Frostmourne in about a month so that I would continue to queue with the "lower GS" group. I was wondering if I got triumph gear to do PVE (ilvl245) would it mean I will not be able to be resegmented back to the lower GS group until relentless season on Frostmourne begins? Thanks