There is absolutely nothing that would indicate what you’re saying will happen, in fact during the call today they said the trend is good and they’re planning on being up to 80% of pre-Covid traffic by summer ‘21. Which is what the leave program is built around.
Of course things could get worse, but they can also dramatically improve, especially as fear subsided and data shows that this disease is not particularly dangerous to the vast majority of people.
In my anecdotal experiences, the Seatac seems to be quite a bit more busy lately. Flights to Mexico have been at or near restricted capacity...people are trying to get back to normal in spite of onerous government restrictions.