Young people voting turnout is always lower than other age groups.
They tend to move around a lot for jobs, relationships etc. and do not have strong community ties.
Staying home on election day is a real option for many of them—they may choose to exercise it this time.
Since it is not virtue signaling to say you are not voting they probably will not brag about it. (ugly double negative :-) )
It's higher nowadays. BLM/ANTIFA (now HAMAS) riots encouraged young folks to vote.