5 years to deorbit passively is correct, but the expected service life is in somewhat similar. Best quote i've got on hand right now is wikipedia:

> "...implement an operations plan for the orderly de-orbit of satellites nearing the end of their useful lives (roughly five to seven years) at a rate far faster than is required under international standards.

Obviously there are many unknowns in factors like hardware reliability or fuel consumption.

All the numbers I have seen were 5 to 7 years of operational lifespan but I can not find a primary source from SpaceX at the moment. I think I also read that there are plans to increase the lifespan eventually with larger satellites, deployed using Starship.