Your theory definitely has merit. Even after nerf, C9 were a bit naive, pretending Chamber was still playable, and it actually worked out a couple times, like in Lotus. But on any other map, they had to move Yay to Sage and Killjoy and we saw how that worked out.
Zekken is one of the most flexible players, his Sova specially hits different, but he is also a top level duelist and SEN now have two of them. TenZ has done well to adjust to Kays. Still feels like a bit of a waste but idk, we havent seen enough of them yet to make that judgement
But you're right. Teams definitely signed a dedicated Chamber player or at least someone who is comfortable on Chamber. Everyone knew that a nerf was on the way but no one knew how bad it would be, so it was a tough situation for the orgs. Lets sign a duelist player PLUS Sayf or Yay. What if they nerf chamber tho? Aight, lets just only one dedicated duelist. What if the nerf isnt that bad? Lose-lose.
Post-deletion (lets be honest, calling it a nerf is being generous), if u look at the teams that did well in LockIn for example, they all either maintained the same squad as last year (didnt bring in a dedicated chamber guy) or they brought in one or two flex players instead (e.g Fnatic with Leo and Chronicle).
The other teams (who planned for Chamber) tho are going through some sort of an adjustment period and I dont know if its fair to say they are fucked. I dont think all of them will come through stronger but the season has merely started and some of them definitely will.
edit: either way, the nerf was good for the game itself. the teams that are struggling, its sad for them now but any team worth their salt will be able to live with it