They are being flagged, but slowly. Since you can currently use Steam’s Family Share as a workaround for any bans that may occur (the bans are tied to Steam account data), whenever an account is banned, all they need to do is create a new Family Share account and they’re back in business. This takes maybe 15 minutes of time and it can be weeks before the detection algorithm actually hits an account (apparently many, if not most of the bans are automated, according to Namco - so far no one who has been banned has been unbanned due to a false positive, from what I can tell - in spite of it being ridiculously apparent that the algorithm has resulted in huge numbers of false positives).
So, it works like this:
Buy 1 copy of game,
Family share DS3 to a newly created account (the account will not be blocked by Namco’s servers).
Start hacking on Family share account.
Family share account gets banned? Make new account and family share DS3 to it.
Thus the real account stays clean and the family share accounts continue to be exploited.
This has been going on for weeks now and seems to be somewhat rampant at this point (Namco has not done a good job with damage control, considering they’re spending a lot of time blaming non-hackers for hacker exploits, rather than fixing the holes being created). As you can imagine, this has resulted in a pretty huge backlash from the non-hackers and is also inspiring some hackers who are doing it “self-righteously” as a response to the poor treatment. Namco has not given a timeframe for when, or if, they will fix these problems.
Something else that was brought to my attention is also that stuff like lag-switches and save editing is not currently being detected on the PS4 version of the game (not detected as hacks, I guess?), for whatever reason.