Sorry for the late post on this matter, WG broke the extractor tool with this game version needed to extract files, and I had to find a fan-made fixed version.
This patch 6 new additional flags were added to the flag.dds file, most of them I can identify.
First Flag – Season 5 Ranked Battle Flag:
Second Flag – Prinz Eugen Special Exclusive Flag:
Third Flag – Unidentified WG… campfire flag?
Fourth Flag – Unidentified “hand in hand”(?) flag
Fifth Flag – WoWS 1 year anniversary flag:
6th Flag – Haifuri Flag (Yes, Haifuri, the anime, this is the crest of the school the story revolves around in, dear god help us all)