Speculation is fun but there are more than two possible announcements.
'As we listened to the merging of two black holes we did not measure any expansion/contraction of space signifying gravity waves like tsunamis through space. This only means the nature of measurement does not register a result in the parameters chosen.
^Waves were detected at light speed.
Leading to more speculation that;
^Waves were FTL.
^ Gravitons seem to have mass.
^Paired gluons may be a particle expression of gravity.
* Perhaps light is relative to gravity waves so we will never detect them.