Darion Atkins, Wesley Saunders and Trice all should be on the Westchester Knicks, right?

Will DaJuan Summers join them? Is Thanasis out if he doesn't make the NBA roster?

Yeah, they should all end up there due to the money in their non guaranteed contracts. Only Trice at this point would interest other teams and no rush there imo.
Thanasis is under contract for the year I believe. We might cut him in favor of someone else cut by another team imo, but it depends. He is probably not ready to play
in the NBA but he might make a defensive impact at some point this year.

I think Atkins, Trice and Saunders definitely play in Westchester. The Knicks can protect 4 players they brought to camp from the d league draft. Not sure if Summers wants to play in the d league or if he got a contract with a partial guarantee as an incentive to play there but I think he is more likely to be there than Thanasis.