Review whether duties, qualifications, pay or employment terms also changed. The significance depends on the actual facts.
Retain both versions
A title-only change should not be invented into a new role, and a substantive change should not be hidden as cosmetic. Update the final account accurately.
Tell the employer early that the letter needs to describe actual duties, so the revision happens alongside other onboarding steps rather than at the last moment. Set a milestone for receiving the second employer's complete duty letter, a separate milestone for the compatibility review against the first role, and a final milestone for confirming authorization before work starts. If the start date shifts or the employer changes the role, some preparation may need redoing, and agreeing in advance what a change costs is easier than negotiating mid-file. Record the delay, revised duties and expected completion, then compare them with the actual admission or status documents. Build a dated review file around the intended start date, current authorization record, employer changes, travel plan, and any I-129 filing evidence. Before starting, compare the finalized employer, duties, duration, supervision, and location with the case that was prepared, then obtain advice if a material fact has changed. A first review creates a reverse calendar tied to the employer’s actual need, credential delivery dates, and the date the letter can be signed.