Back in the original series a successful German Suplex was a sure win, but not here. False Yellow Devil indirectly explains why when he says why he doesn't fear Tiger Mask's new move: just as he could counter a new move after seeing it once, the suplex, as a rather old move, is so well known that pretty much everyone knows how to counter or at least soften it.
That also explains why the new Tiger Mask didn't recycle the Fujiyama Tiger Breaker: while the only effective counter is incredibly hard to pull off, the fact is that it exists and is known, and Yellow Devil is large and strong enough to pull it off.
Not to mention that his own killer move eventually gets countered later in the series, proving his point.
As Spring Tiger, Haruna uses a rather old school style attacking her opponents' legs with grappling moves to disable them. Being self-trained, she stuck on something relatively simple yet effective.
Speaking of her style, it worked well against Miss X but failed against Milk. This is actually explained later in the series by Tiger Mask when he fought Miracle III, Tiger's Den coach: just as Haruna, Miracle III sticks to simple moves he has honed to perfection, but he's easily anticipated by an experienced wrestler as Tiger Mask-or like Milk when compared to Haruna.
And why does it work when Tiger Mask does it to the Third? Because Tiger Mask, being a far more experienced fighter than Haruna and more cunning than Miracle III, found a way to mask it, simply sneaking a few shots in the same place on the left arm before using a chance occasion to inflict a Game-Breaking Injury, resulting in the Third being unable to properly execute the Sacrifice and later to counter a Tiger Fang.
And why Miss X reacted to the move that was inflicting the Game-Breaking Injury by giving Mr. X a towel to throw? Because she had already been through it, and knew from experience what would happen: either the Third submitted, or injured himself as he got out.
Why are the wrestlers under Tiger's Execution and waiting for Hell in the Hole allowed to receive and send (censored) mail? To keep their friends and family on the outside from growing suspicious and possibly start investigations that could threaten Tiger's Den.
Fukuwara Mask use of the ''kancho'' makes perfect sense once one finds out he is a traitor from Tiger's Den and their former chief coach: it is both ridiculous, fitting his comedic gimmick, and utterly devastating due to hitting an area that is impossible to reinforce, fitting his former membership of Tiger's Den and role as the main coach.
Naoto Date doesn't return nor gives any sign he's alive. As fifty years have passed he could have easily died... But even if he were still alive, he cannot come back to Japan: in the final episode of the anime he beat Tiger the Great to death on live television and slapped away Baba and Inoki when they tried to stop him... And under Japanese law this is punisheable with death, meaning that it will never fall in prescription. If he came back and contacted his old friends they would either have to report him or become accomplices of a wanted murderer, and Naoto wouldn't want to force this choice on them.
During most fights Tiger The Third crushed Tiger Mask or Tiger the Dark when he fought them solo, but in the end loses to Naoto in a solo match... Where Naoto is wearing a mask made by half of his old Tiger Mask mask and half of Takuma's Tiger the Dark's mask. At least in spirit, The Third is fighting both of them, and thus loses just as it happened when he fought them both in a tag match.
A flashback shows that Ken closed down his car repair business to train Naoto. Suddenly, Haruna's shows of Greed makes quite more sense... Especially as she was expecting to work at the repair shop as soon as she was out of school and later even inherit it.
that the WWE has banned it unless the wrestler has special permission (others promotions, the state of Tenneessee, Mexico, the United Kingdom, and the MMA Unified Rules have banned it completely). Then why does GWM, Fictional Counterpart to WWE, allow him to use it? Because he's from Tiger's Den in a promotion controlled by them and good enough that WWE could have given him permission.