Yes and no
If the body is preserved as a shrine – most certainly yes. But the help is to a limited degree since the physical body is not there. Preserved as in Samadhi
If the perfected yogi has dissolved all bodies maybe. But takes a very advanced disciple to bring him down.
This is what Yogananda said
I WILL ALWAYS WATCH FOR EACH OF YOU:
” God has sent them to me, and I will never forsake them. […] Even when I’m gone, my help will always reach sincere devotees around the world who stay tuned with me.
Never think for a moment that, when you have abandoned
this physical form, I will not stand any other way with you. When I no longer find myself in this body, I will be so
Deeply interested in everyone’s spiritual well-being as I am now.
I will always watch over each of you, and whenever a sincere devotee thinks of me in the silent depths of his soul, he will know that I find myself next to him “. PARAMAHANSA YOGANDA
They can watch. Emotionally super
Bhavin