FWIW, when a bike is shipped to a bike shop from a manufacturer, the seatpost is not installed. As part of the assembly process, the bike shop, not the manufacturer, applies any grease, assembly paste, etc to the seatpost/seat tube. This fact alone doesn't prove or disprove anything, but I will note, for example, that when a steel framed bike is shipped, and it's to be equipped with an aluminum seatpost, the seatpost and seat tube are dry when it arrives at the bike shop in a box. Again, adding grease (in the case of the steel frame example) is part of the assembly process.