Doesn't matter if they are really cheaters/fixers or not to be on the list. What matters is the scorelines and the chokes. Also you would suspect that the betting companies contact ATP if there was a major livebet against a seemingly winning player that then suddenly started to lose. In some cases the gambler probably just took a major chance but normally you don't risk large amounts on bets like that.
Just to take a few of the names.
Kohlschreiber. Plays way more 3-set matches than your "average" player. Most pros actually close out matches in 2 when they win the first set. Kohli has lost more than any normal pro would do when winning the first set. Also lost plenty of matches from having multiple MPs
Fognini. Look at the scorelines in some his matches. Could win a match and be favorite in the next but then get bageled like a clown and lose easily. Very strange player
Gabashvilli/Korolev. Sometimes do so many errors that any sane person must think they do lose intentionally. I'm not sure myself
Troicki/Cilic. Probably both there just for choking tendencies. Dunno how many matches they have lost from being up.
I don't find the list that surprising because it's a few of the players I would say are most interesting to bet against vs lower rankeds or from winning positions because they are "chokers" or inconsistent.
How is Dolgopolov not on the blacklist? He is hands down the most blatant fixer on tour. Chela is also not on the blacklist, and he is absolutely top 5.
Dolgopolov is probably too "new" to be included on the blacklist yet. If he keeps lining really weird scorelines maybe he will get on the watchlist very soon