I want to delay my plan of US travel and change my employer at my parent country outside of US, Will there be any risk?

Hi,

I have got my H1 stamped through company A. Now because of some circumstances, I don’t want to fly to US right away and join a new company B outside of US. Still I want my H1 to be valid as I am planning to go to US after few years. I have below doubts:

  1. Can my current employer A revoke/cancel my H1b?

  2. If Company A revoke my H1b and after 2-3 years I want to go to US and I am able to get any employer who is ready to send me to US, do I have to go through lottery process again or as I am already having a approved petition, I will be able to use that.