Winding down can still mean they have to have certain staffing in a particular seat. They can sometimes poach from another base, but that tends to add a lot of extra credit/duty/pay/hotels for the same flying.

IDK what they're planning on doing with SEA7ER or when they're planning on doing it. But sometimes they have no choice but to staff it til they close it. There are frequently numerous and compounding downline considerations, just like with bypass pay or "double training." It may not make sense from a zoomed in individual perspective but often does when everything is taken into consideration.