That's exactly what happened in one of the hallways in one of buildings at my old university.
(Click to enlarge)
The original ceiling was removed as part of asbestos abatement in 2013, when they installed the replacement drop ceiling they chose to lower the ceiling 2' to hide the piping that was added over the years. It turns out they never removed or at the very least disconnected some of the original light fixtures that are now concealed by the new drop ceiling. The new lighting iare two lamp 2x4 F32T8 recesssed troffers, the old lighting was 1x4 two lamp surface troffers.