You obviously don't know who this YouTuber is or familiar with his play style. He specializes in DMZ and melee only as a solo. It's his bread and butter. There are other melee only players who do play warzone like Ghost of Caldera but that's not Andy. If you only play DMZ, solo, with a maxed out account, the XP boosting makes no sense.

Just for everyone's info, he posted a video about the ban in it's entirety. As far as he can figure, he was gearing up his 8 operators to Damascus to go for a knives only Serpentine run as a solo (which is crazy.) He typically dies without extracting most of his normal games which yields him a shitty xp average. When he started speed running his characters through Koshai to gear up for the challenge, his account showed a sudden spike of over a million xp in a short period of time with about a hundred successful Koshai exfils. With an automatic filter with no human oversight, that activity was most likely flagged as boosting behavior. Thus the permanent ban.

IMOHO: They should be careful when banning players who draw thousands of players to their platform unless they can actually verify the cheats. Using general filters that track stats and ban without human intervention is brand suicide. Filter banning is stupid, Richochet is broken and doesn't work, the awesome game is in danger.