Either Coulson is really and truly gone by the second-to-last episode of the season or the entire cast was in on a conspiracy to conceal secrets as much as possible.
Given that the most legendary droppers of MCU spoilers aren’t part of the S.H.I.E.L.D. cast, perhaps they really are keeping the secret!
Chloe Bennet shared her thoughts on Daisy dealing with Coulson’s absence to TVLine while the cast was filming the penultimate episode of Season 6, and nobody on set reportedly talked about Coulson in the present tense.