8 USC 1451(a):
> a) Concealment of material evidence; refusal to testify It shall be the duty of the United States attorneys for the respective districts, upon affidavit showing good cause therefor, to institute proceedings in any district court of the United States in the judicial district in which the naturalized citizen may reside at the time of bringing suit, for the purpose of revoking and setting aside the order admitting such person to citizenship and canceling the certificate of naturalization on the ground that such order and certificate of naturalization were illegally procured or were procured by concealment of a material fact or by willful misrepresentation
According to USCIS, the misrepresentation need not be but-for material. That is, you only need to show that the omission or misrepresentation was relevant to the naturalization inquiry. But you do not need to prove that the government would have denied naturalization had it known the true facts. In that respect, the standard is similar to 18 USC 1001, which has been applied extremely broadly in federal prosecutions. The second Trump administration has much smarter lawyers than the first one, and I'd count on them to be aggressive about using the full scope of section 1451(a).
Not because they expect people to say “yes”, but because if they find out later you hide information about your involvement in WW2, they deport you for lying.
No need to prove you were an actual Nazi. You withheld information which is enough grounds for revoking citizenship.