No player will have 233 ilvl; only the last two bosses drop that iLevel and most likely it’ll be a weapon for some classes, trinket for others, and a shoulder / head piece.
For all intents and purposes the difference between a high-rated PvPer and a fully completed Mythic raider will be around 3-4 iLevels; the biggest advantage will come from most likely powerful burst trinkets / weapon procs / set procs that a PvP’er likely won’t have.
Tit for Tat, if both players were equally skilled at PvP; I have no doubt that the PvE geared player will utterly destroy the PvP player.
However, PvE’rs that can PvP are rare / few and vice versa; two entirely different gameplay styles.
It doesn’t really matter anyway; 950 guilds completed 12/12 M and only 13847 players are 2.2k rated or higher.
Sources for my data were check-pvp and wow-progress.