Okay, Ill cut to the points.
Roaming: Bjerg usually does this, but you are right, post assassin meta, its dropped. Its dropped all over. and I think many of his opponent roams are due to TSM losing and having a lack of map pressure, getting caught, more so than Bjerg giving the freedom to do so, Whereas when TSM is winning the map, it would give Bjerg more freedom to roam.
Versatility: I do want to mention that while you are correct, Bjerg has always favored assasins, when those go out, he suffers. That the comment about Bjerg vs Faker (champ pools only) its actually closer than you think.
Bjerg has 28 champs played, Faker of all people has 34. And Faker has significantly more games played due to the structure of Bo3 vs Bo1 in NA
What IS interesting though, is that what you said about this tournment isn't wrong. Bjerg/TSM truly misread this meta and believed Cho Gath was a power pick (and it was a really popular pick not to long ago) but it even leads into ... something more.
Bjerg has played both Azir and Cassio, this season. Each one time and one time early. Bjerg played Azir and lost at IEM San Jose at pre season, never played him again. Cassio he played vs TL, they lost and he never played her again.
It does seem like sometimes they lose with a pick, and it might not even have been directly the picks fault... and its gone right?
It seems they tunnel on such a small champion pool. Bjerg spammed Orianna at s4 worlds, SSW banned Ori from Bjerg every game at worlds because according to Bjerg or tsm pretty much if Bjerg got Ori in scrims TSM won. This tourny Orianna was seen as a solid pick Where the hell was it?
Adaptablity: This ones interesting, because in the past it had seemed reliable that bjerg would have the necessary picks to hold up. Bjerg picked up Viktor for MSI, having not played it very well, and drew bans on it after. Even in LCS he picked up Urgot within a week (before Urgot became the pick or ban he is today)
This tourny, he did nothing. Its truly baffling that a player like Bjerg who can obviously play the assasins if called to do so, has experience on other champions... but simply doesn't play them due to lack of practice? perhaps?
Shotcalling and Leadership I agree. Bjerg hasn't looked like a natural shotcaller and leader, and he definitely lets his emotions get to him. I do think that TSM legends or any show like that will show you sides to any player you wouldn't believe, but I do think that he will need to mature, in time.