If Lewis-Skelly moves into midfield, I don't think it would be as a holding 6. He is more a dynamic player than a positional one. I think he's too good at LB to mess with, at least right now, and with Rice, Ødegaard, Merino, and to an extent Havertz, we are pretty loaded at the 8.
Calafiori is a really compelling talent but he did not look great defending 1-v-1s out wide last season. I'm not totally sure that his future is at LB. He could end up an inverting LCB (with the LB tucking inside when he moves up). Links to Jorrel Hato are popping up again, and he may be a more natural defender on the outside, allowing Calafiori to play more centrally. I don't totally know.
I am predicting an absolutely mega start to the season for Havertz next year.
Glad to see reports we're making Nico Williams a serious offer. He is raw and not quite where we need on end product, but he is a natural fit tactically and he's as good as anyone in the world at beating his man and creating space for a shot/final ball.