My approach to this theory is we’ve seen piccolo sacrifice himself for gohan everytime when he sees a danger coming towards his way, piccolo took care of gohan when goku was running down snake way in 2003, their strong communication was built when piccolo fired cannon beam towards raditz being hold by goku, and that killed them both since goku asked for it, from that time piccolo took care of gohan.
training him, feeding him but most importantly protecting him by his own life.
in the tournament of power they seem to be working as a team, but they have strong opponents this time and they are namekians too from another universe(6).
The theory is that piccolo will sacrifice himself for gohan as he sees a powerfull attack coming towards him and it will knock him off the stage, this will trigger gohan’s new form just like goku’s ultra instinct to be facing jiren.
at the end this is just a theory and nothing is confirmed yet, stay tuned to get and more theories and news.