This question will be resolved by checking Wikipedia's list of socialist Congresspeople in January 2025, after the 119th Congress has convened.
According to Wikipedia, there are currently 9 politicians in the United States Congress that are currently or were previously socialists by party affiliation or self-declaration.
Will the number of socialists in Congress rise to at least 10 after the 2024 elections?
1,000
3.00Greg Cesar, Summer Lee, AOC, Rashida Tlaib, Bernie Sanders, and Danny Davis, all self-described socialists on Wikipedia's list, have won their elections.
Cori Bush was defeated in her primary by Wesley Bell, who won her seat. Bell is not a self-declared socialist.
Jamaal Bowman was defeated in his primary by George Latimer, who won his seat. Latimer is not a self-declared socialist.
I'll see about waiting for Wikipedia to update their list, since I am not sure if there were any new socialist candidates who won elections. But if no new socialists were elected to Congress, then the total should be 6, which is less than 10 necessary for this question to resolve YES.