SH to Simple

Secure 2.0 allows mid-year Simple to 401k but is that a two way street?

Section 332, Employers allowed to replace SIMPLE retirement accounts with safe harbor 401(k) plans during a year. Section 332 allows an employer to replace a SIMPLE IRA plan with a SIMPLE 401(k) plan or other 401(k) plan that requires mandatory employer contributions during a plan year, and is effective for plan years beginning after December 31, 2023.

Can I terminate a SH 401k and replace with a Simple in the same year?  

Why would you want to do that?  Keep the SH 401k.

Agreed, and believe it's a one-way street. (And don't say but you're only going one way!)