No, closely timed filings do not guarantee closely timed decisions. Evidence, follow-up requests, classification, and available visas can produce different schedules. A derivative route remains linked to the principal but likewise does not guarantee simultaneous appointments or admission.
Separate determinations, separate waiting
That divergence matters if the household plans to relocate as a unit: check category and chargeability early, before either fee is paid, so the possibility of staggered interviews is priced into the plan. Note also that a pending case authorises no employment in the United States. Permanent resident status generally authorises work on admission, and any independent work permission a spouse already holds operates separately from these filings.
The official description of processing in weeks is a description, not a guarantee, so build planning around events you can observe: the vetting outcome, the instruction to make the gift, the category determination, and the visa interview. The official transfer terms include new vetting, and successful cases remain subject to the applicable EB-1 or EB-2 conditions and visa availability. A missed email does not itself guarantee an extension, approval or a new processing date; use the actual official instructions. A first review should order eligibility evidence, official vetting, payment instructions, payment confirmation, and the separate immigration process.