I find it interesting that the thing they are going to ban at Feast of Blades is actually not that powerful except under certain circumstances (specifically Tzeentch). I love the Grimoire of True Names just for its randomness.Plus on a few occasions I have managed to get a 2++ invunrable on my Beasts of nurgle.
I just don't think GW care about tournaments in the way they used too and events like Throne of Skulls emphasis the playing of the game rather than the winning.
Yeah, GW definitely doesn't care about 40K tournaments anymore. Super sad.
Which is why people like the TO organize at Feast of Blades is making a ban/restricted list.
And your right, the Grimore of True Names is not that powerful. Only in one situation with the right units does it create an OP combo. And it's that one combo (screamerstar) that we, the players, need to find a fix for. Is banning the Grimore the right option? I don't know. But it's one option that would work.