It doesn't change TD eligibility directly, but delays caused by resolving a duty or credential mismatch can push back the whole household's moving timeline. If a spouse plans to work, that needs its own review regardless of how the principal engineer's case resolves.
Keep the household timeline flexible until the fit is confirmed
Avoid locking in a moving date, school enrollment, or housing lease until the duty and credential questions are settled, since a rewritten offer letter or a licensing delay can add real time to the process. A spouse hoping to work in the U.S. should have that question reviewed on its own track, since TD status alone does not authorize employment.
Build in a buffer rather than assuming the engineering role will resolve on the employer's preferred schedule. Two questions are worth settling in the same week as the duty description. Ask whether each dependant already holds a status or visa that would need to be surrendered or allowed to lapse, since that decision is far easier before travel than after it.
Then establish who in the household depends on employment income, because where a spouse cannot work the family budget, rather than the immigration file, becomes the binding constraint on when a move can happen. Hypothetical example: an environmental engineer's spouse holds a professional registration that lapses if unused for two years, so the household plans a return-to-practice route alongside the move instead of discovering the problem at a renewal date. Write both answers down beside the intended moving date rather than carrying them in conversation.