While everyone's bashing on IMT's bad picks, I'd like to offer a different perspective.
I think it's a bit unfair to say that IMT didn't know that the tank meta was coming. The resources were everywhere and everything pointed to that direction, and it would be silly to think that so many casuals know this over IMT's analysts. Even though Pobelter said in the postgame interview that they misread the meta, I think it wasn't due to not knowing that the tank meta exists. Either way, Pobelter at least implied that IMT got the picks they wanted.
IMT decided to try their hand at countering this meta, employing a heavy fast push strategy with triple ADC + Karma support and relying on the trademark snowballing strength of the team during the regular season and trying to end the game before Hauntzer could scale up and be immortal (no pun intended). Because Huni refuses to play tanks (this in itself is a large issue, however), IMT decided it's probably best to find an alternative playstyle. Apparently the strategy had success in scrims (I mean, they weren't just going to bring it out on stage right?), and vs. a team that had issues coordinating in the regular season, they thought it would be a good idea to pick the strat. And it was working for a while too, until they got Fnatic Deathbushed and then tilted the rest of the series.
Of course, this isn't to discredit TSM, who performed exceptionally in this series and withstood the early pressure and turned it around.
I'm just glad that Darshan can adapt to the tank meta.